Halogenated acrylates and polymers derived therefrom

ABSTRACT

Acrylates having a high degree of halogenation, as well as polymers that include one or more mer units derived from such acrylates provide materials having tailorable optical and physical properties. The polymers find utility particularly in optical devices including optical waveguides and interconnecting devices.

BACKGROUND INFORMATION

[0001] 1. Field of the Invention

[0002] This invention relates to acrylates in which a large percentageof hydrogen atoms have been replaced by halogens and to polymers thatinclude mer units derived from such halogenated acrylates.

[0003] 2. Background of the Invention

[0004] Optically transparent polymers, especially those used fortelecommunication applications, must have low absorptive loss in theinfrared wavelengths, typically 1260-1360 nm and 1480-1580 nm. However,because these wavelengths are close to overtones of carbon-hydrogen bondvibration frequencies, minimization of the number of carbon-hydrogenbonds is desirable. While some organic compounds with few C—H bonds areknown, additional considerations of optical transparency, ease ofpolymerization, refractive index, chemical and mechanical stability, andthe need to compete on a cost basis with glass prevent many suchcompounds from widespread use in polymeric optical devices.

[0005] U.S. Pat. Nos. 3,668,233, 3,981,928, and 4,010,212 describeacrylic acid esters (i.e., acrylates), prepared from esterification ofacrylic acid with perfluorotertiary alkyl alcohols such asperfluoro-t-butyl alcohol, that can be used as inert heat exchangefluids and as homopolymeric water- and/or oil-repellent surfacecoatings.

[0006] European Patent Application No. 282,019 describes highlyfluorinated, transparent acrylates specifically tailored for opticalarticles. These materials are prepared from cyclic or bicyclic alcoholscontaining few or no carbon-hydrogen bonds.

[0007] U.S. Pat. No. 3,544,535 describes the preparation andpolymerization of 2-(pentafluorophenyl)hexafluoroisopropyl acrylate.Optical properties of the polymer are not described.

[0008] U.S. Pat. Nos. 3,520,863 and 3,723,507 describe a number ofperfluorocycloalkyl acrylates and polymers thereof. Use of tertiaryalcohols is not reported, and optical properties of the polymers are notdiscussed.

[0009] U.S. Pat. No. 5,045,397 describes the preparation and use ofcertain adhesives to be used in optical systems. A polymeric adhesive ofa specified refractive index is prepared by copolymerization ofspecified monomers of known refractive indices. While some lightlyfluorinated monomers are described, highly fluorinated monomers are notdisclosed.

[0010] U.S. Pat. No. 5,223,593 describes acrylate monomers and their(co)polymers designed to have low C—H bond density relative topoly(methylmethacrylate) so as to reduce vibrational band intensities inplastic optical fiber cores. Absorbance at 600-1200 nm was reduced, butabsorbance at higher frequencies is not reported. The describedacrylates were prepared from highly fluorinated primary alcohols.

[0011] U.S. Pat. No. 5,093,888 describes a polymeric optical device(specifically, an injection-molded Y-shaped splitter waveguide) thatuses an amorphous polymeric adhesive that includes 2,2,2-trifluoroethylmethacrylate having a refractive index of 1.418 to hold optical fibersin a polytetrafluoro-ethylene spacer containing a fluorinatedpolyetheretherketone core.

[0012] U.S. Pat. No. 5,311,604 describes a method of manufacturing apolymeric optical interconnect. Useful polymers are said to be thosetransparent to the wavelength of light to be utilized. Listed examplesinclude poly(methylmethacrylate) (“PMMA”), polycarbonates,polyurethanes, polystyrenes, and polyolefins. In one example, a“copolymer of deuterated PMMA-d8 (sic) and tetrafluoropropylmethacrylate” is used to adhere optical fibers to a molded PMMA device.

[0013] U.S. Pat. No. 5,343,544 describes a polymeric opticalinterconnect. The device includes polymeric substrate and coveringmembers that can be fabricated from, for example, a combination offluorinated and non-fluorinated photopolymerizable (meth)acrylate anddi(meth)acrylate monomers. The same combination of monomers is said tobe useful for sealing optical fibers in the device. Substitution offluorines for hydrogen atoms in the polymer is said to be capable ofreducing the refractive index of the polymer and to reduce losses innear infrared wavelengths, but no example of a haloacrylate-only systemand no indication of the degree to which loss or refractive index can becontrolled are given. Copolymerization of two or more monomers is saidto be able to provide a copolymer having a tailored refractive index.

[0014] Devices used in telecommunication applications (such as thosedescribed in '604 and '544, above) preferably meet certain standards forperformance, durability, and the like. The standards most commonlyreferred to in discussing such devices are the so-called “BellcoreSpecifications”. Requirements for fiber optic branching componentsinclude parameters for optical loss (i.e., loss that is in excess overthat which is inherent in the device), useable wavelength ranges,resistance to performance variability caused by temperature andhumidity, optical cross talk, water immersion, flammability, etc. Allsuch parameters can depend, at least in part, on the materials used tomake the device. For example, materials must have very low absorptivelosses in the wavelength regions of 1260 to 1360 nm (nominally 1310 nm)and from 1480 to 1580 nm (nominally 1550 nm), over which ranges lowlosses must be maintained under extreme temperature and humidityconditions. For a 1×2 splitter, the inherent loss is calculated to be3.01 decibels (dB), where a decibel is defined as −10 log(I_(o)/I_(i))in which I_(o) is the intensity of the output and I_(i) is the intensityof the input. Maximum allowable excess loss in a 1×2 splitter isquantified as, e.g., no more than 0.25 dB per fiber plus no more than0.5 dB per waveguide junction connecting an input fiber to an outputfiber.

[0015] Presently available materials other than glass have not proven tobe able to meet all, or even most, of these rigid requirements.

SUMMARY OF THE INVENTION

[0016] Briefly, the present invention provides halogenated acrylateshaving the general formula

[0017] wherein

[0018] M is H, CH₃, F, Cl, Br, I, or CF₃; preferably M is H, F, or Cl;most preferably M is H because of availability, reactivity, and thermalstability;

[0019] A is oxygen or sulfur; and

[0020] Z can be a group having a maximum of 150 carbon atoms and can be

[0021] in which each R¹ independently is F, Cl, or Br;

[0022] in which each R² independently can be

[0023] (a) a perfluorinated, perchlorinated, or per(chlorofluoro)

[0024] (i) C₁-C₂₀ aliphatic group,

[0025] (ii) C₃-C₂₀ cycloaliphatic group,

[0026] (iii) C₆-C₂₀ aryl group,

[0027] (iv) C₇-C₂₀ aralkyl group, and

[0028] (v) C₇-C₂₀ alkaryl group,

[0029] (b) F, Cl, Br, I, Q (defined below), R⁴COO—, R⁴O—, —COOR⁴,—OSO₂R⁴, or —SO₂OR⁴, wherein R⁴ is any group from (a)(i), (a)(ii),(a)(iii), (a)(iv), and (a)(v),

[0030] or any two adjacent R² groups together can form a perfluorinated,perchlorinated, or per(chlorofluoro) cycloaliphatic or aromatic ringmoiety in which n fluoro or chloro groups optionally can be replaced byR² groups where n is a whole number in the range of 0 to 25, and R² isas defined above, wherein Q is

[0031] in which A is as defined as above, with the proviso that all R²groups in the molecule can be the same only when R² is not Cl, F, Br orI, and each R³ independently can be

[0032] (a) a perfluorinated, perchlorinated, or per(chlorofluoro)

[0033] (i) C₁-C₂₀ aliphatic group,

[0034] (ii) C₃-C₂₀ cycloaliphatic group,

[0035] (iii) C₆-C₂₀ aryl group,

[0036] (iv) C₇-C₂₀ aralkyl group, and

[0037] (v) C₇-C₂₀ alkaryl group,

[0038] (b) F, Cl, Br, I, Q (defined above), R⁴COO—, R⁴O—, —COOR⁴,—OSO₂R⁴, or

[0039] —SO₂OR⁴, wherein R⁴ is any group from (a)(i), (a)(ii), (a)(iii),(a)(iv), and (a)(v),

[0040] or any two adjacent R³ groups together can form a perfluorinated,perchlorinated, or per(chlorofluoro) cycloaliphatic or aromatic ringmoiety in which n fluoro or chloro groups optionally can be replaced byn R³ groups where n is a whole number in the range of 0 to 25, and R³ isas defined above;

[0041] (3) —C(R_(f))₂E in which

[0042] both R_(f) groups together can be part of a perfluorinated,perchlorinated, or per(chlorofluoro) cycloaliphatic ring group or eachindependently can be a perfluorinated, perchlorinated, orper(chlorofluoro)

[0043] (a) C₁-C₂₀ aliphatic groups,

[0044] (b) C₃-C₂₀ cycloaliphatic groups,

[0045] (c) C₆-C₂₀ aryl groups,

[0046] (d) C₇-C₂₀ aralkyl groups, or

[0047] (e) C₇-C₂₀ alkaryl groups,

[0048] (f) C₄-C₂₀ heteroaryl groups,

[0049] (g) C₄-C₂₀ heteroaralkyl groups,

[0050] (h) C₄-C₂₀ heteroalkaryl groups,

[0051] wherein the heteroatoms can be one or more of O, N, and S atoms,with the proviso that at least one R_(f) group includes one or more ofthe following:

[0052] (1) at least one straight-chain C₄-C₂₀ aliphatic or C₄-C₂₀cycloaliphatic group,

[0053] (2) at least one ether oxygen atom, and

[0054] (3) at least one branched C₃-C₂₀ aliphatic group, and

[0055] E can be R_(f),

[0056] wherein R¹, R², R_(f), and Q are defined as above; or

[0057] (4) —CR_(f)(E)₂,

[0058] wherein each E independently is as defined above, and R_(f) is asdefined above.

[0059] In another aspect, the present invention provides a polymer thatincludes at least one mer unit derived from the above-describedhaloacrylates as well as optical devices and optical materials made fromsuch a polymer.

[0060] In yet another aspect, this invention provides di- andtri-functional acrylates as crosslinking agents with low hydrogencontent, usually no more than the required three H atoms around eachacrylate group.

[0061] In yet another aspect, this invention provides ether-containingperhalo-, preferably perfluoro- and perchlorofluoro ketones asintermediates to low H-content acrylates. Preferred compounds include1,2-dichloroperfluoroethyl ether and 1,1,2-trichloroperfluoroethyl etherderivatives which can be prepared by the direct fluorination of a1,1-dichloroethyl ether and 1,1,1-trichloroethyl ether, respectively.

[0062] In yet a further aspect, this invention provides1,2-dichloroperfluoro/per(chlorofluoro) ethers useful in the synthesisof the above acrylates and also useful as precursors to perfluorovinylether monomers optionally substituted by functional groups. Preferredperfluorinated ketones have the structure R⁵ _(f)OCF₂COCF₃, R⁵_(f)OCF₂COCF₂Cl, and R⁵ _(f)OCF₂COCF₂OR⁵ _(f), wherein R⁵ _(f) is alinear perfluoroalkyl or perfluorooxyalkyl group having from two totwenty carbon atoms.

[0063] In this application, the following definitions apply unless acontrary intention is explicitly indicated:

[0064] (a) “group” or “compound” or “monomer” or “polymer” or “mer unit”means a chemical species that allows for substitution by conventionalsubstituents that do not interfere with the desired product such as, forexample, linear or branched alkyl or haloalkyl groups;

[0065] (b) “optical coupler” or “interconnect” means a device that joinsone or more input optical fibers to one or more output optical fibersand includes devices such as splitters and combiners;

[0066] (c) “acrylate” includes corresponding “methacrylate” and other2-substituted acrylates throughout this application; and

[0067] (d) subscript “_(f)” refers to a perhalogenated group.

[0068] The halogenated acrylates of the present invention haverelatively few C—H bonds, usually no more than three (i.e., those aroundthe acrylate unsaturation) or no more than five (around methacrylateunsaturation). This dearth of hydrogens means that these compounds havevery little absorption in the infrared wavelengths of interest, i.e.,1260-1360 nm and 1480-1580 nm. Because these materials can be used inoptical applications, particularly devices that guide light such aswaveguides and optical interconnects, minimizing loss of signal due toabsorption by the material of which the device is made is very importantand desirable.

[0069] Despite the fact that the acrylates of the present invention arehighly halogenated, they are relatively easy to polymerize, areoptically clear, have low optical loss, are liquids or solids withrelatively low melting points or dissolve sufficiently in lower-meltingcomonomers, provide amorphous polymers with good thermal stability andhigh molecular weights, and provide polymers (typically copolymers)having indices of refraction that effectively match those of glassoptical fibers. These characteristics make them excellent candidates foruse as materials in polymeric optical devices, especially waveguides andoptical couplers.

[0070] Presently available optical devices made from glass aremanufactured in one-at-a-time, handwork operations that are very laborintensive and prone to low productivity. Polymers of the invention canbe processed automatically by known polymer processing methods intooptical devices that are physically robust and are substantiallyidentical, leading to significant improvements in product reliabilityand economics. Polymeric optical devices of the present invention can bemass produced and can be handled under severe field conditions withoutundue damage and/or loss of properties.

BRIEF DESCRIPTION OF THE DRAWING

[0071]FIG. 1 is a comparison of absorption vs. wavelength plots of apolymer derived from one embodiment of the halogenated acrylates of thepresent invention with two comparative halogenated polyacrylates.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0072] Halogenated acrylates of the present invention are useful forvarious optical applications. They display several highly desirablecharacteristics including ease of polymerization, optical clarity,favorable melting points, and polymers therefrom exhibit very littleabsorption in critical infrared regions (i.e., 1260-1360 nm and1480-1580 nm), thus minimizing optical loss due to absorption. Whenhalogenated acrylates of the present invention are polymerized, or whentwo or more are copolymerized, the resulting polyacrylate is amorphous,has good thermal stability, has relatively high molecular weight, andcan have an index of refraction that effectively matches that of a glassoptical fiber.

[0073] Further, halogenated acrylates of the invention can becopolymerized to prepare copolymers having specifically desired physicalproperties, such as refractive index (n_(λ)), glass transitiontemperature (Tg), optical absorption, etc. In spite of publishedtheories of predicting such properties based on additivityconsiderations (e.g., the Fox equation for Tg), we have found thatcertain combinations of monomers, particularly those having highmolecular bulk, give copolymers having unpredicted refractive indices,and that physical properties and chemical reactivities of these highlyhalogenated monomers cannot be predicted a priori. Further, we havefound that synthesis and measurement are required to determine the exactrefractive index and reactivity of these highly halogenated monomers,and that copolymers must be prepared in order to determine their preciserefractive index and melting point; calculations and predictions areinsufficient. Table 1, below, shows the disparity between calculated andobserved refractive indices for a number of homopolymers of theinvention.

[0074] Halogenated acrylates of the present invention have the generalformula

[0075] wherein M, A and Z are as defined above.

[0076] The portion of the molecule other than the Z moiety defines atypical acrylate when A is oxygen and a thioacrylate when A is sulfur.As those skilled in the art of polymer science are well aware, acrylatesare a broad class of polymerizable materials, the chemistry of which iswell defined.

[0077] Although M typically is H, other substituents such as CH₃, F, Cl,Br, I, or CF₃ can be used in place of hydrogen. However, any suchsubstitution should be done while keeping in mind the desiredperformance characteristic(s) of the material (e.g., polymer index ofrefraction, ease of polymerization, liquidity at the temperature(s) ofuse, very little absorption in the critical infrared regions, monomeravailability, and cost, etc.).

[0078] Many acrylates meet several of the aforementioned criteriaregarding acceptable materials. For example, acrylates have relativelylow melting points and can be polymerized to amorphous polymers withhigh molecular weights. However, heretofore available acrylates have notbeen able to meet those criteria relating to optical performance.Specifically, such acrylates have had unacceptably high absorption inthe aforementioned infrared wavelength regions. In contrast, halogenatedacrylates of the present invention have acceptably low absorption inthese wavelength regions.

[0079] In the general formula set forth above, A can be either oxygen orsulfur. (Although the term “acrylate” normally would include only thosecompounds where A is oxygen, for present purposes, the term includesthose compounds where A is sulfur.) For reasons of availability ofstarting materials, hydrolytic stability, and potential odors, thosecompounds where A is sulfur are not as preferred as those where A isoxygen.

[0080] The Z moiety in the above formula serves at least two importantfunctions. First, it assists in tailoring the index of refraction of thepolymerized halogenated acrylate. Because the index of refraction ofoptical fiber cores and cladding layers generally fall in the range of1.44 to 1.46, this is a desirable index of refraction range for opticalmaterials of the invention. Preferably, homopolymers prepared from thehalogenated acrylates of the present invention have an index ofrefraction of between about 1.36 and about 1.56. Further, acrylatemonomers can be mixed to provide copolymers having an index ofrefraction in the desired range. Since the index of refraction of mostglass used in optical fiber cores is approximately 1.457, a preferredindex of refraction of a copolymer of the invention can be approximately1.450. It is to be appreciated that in an optical device the index ofrefraction of a core desirably is slightly higher than the clad, and thecore index of refraction desirably matches the index of refraction of anoptical fiber core, which fiber is connected to the device. Typically,the index of refraction of the clad in a device can be slightly lessthan that of the core (the difference preferably is about 0.007).

[0081] Second, the bulk of the Z moiety assists in keeping low theweight percentage of hydrogen in the halogenated acrylates of thepresent invention. To reach acceptably low absorption in the infraredwavelength regions of interest (i.e., those wavelengths where overtonesof C—H bond vibration frequencies absorb), keeping the weight percentageof hydrogen in the compound as low as possible is desirable. Anempirical rule regarding the relationship between molar volume andabsorption loss at 1480 nm has been developed through experience: tokeep absorption loss less than 0.1 dB/cm (at 1480 nm), a haloacrylate ofthe invention wherein A is O and M is H desirably has a molar volume ofat least 150 mL/mole, more preferably at least 200 mL/mole, and evenmore preferably at least 250 mL/mole. The correspondinghalomethacrylates wherein A is O and M is CH₃ require higher molarvolumes to meet the 0.1 dB/cm (at 1480 nm) absorption loss criterion. Toassist in meeting this target molar volume, Z serves the importantfunction of increasing the molecular volume without adding hydrogenatoms to the halogenated acrylate of the present invention so that theeffect of the hydrogen atoms surrounding the double bond is minimized.Copolymers of halogenated acrylates where one or more of the monomersincludes a relatively small Z group and one or more monomers includes arelatively large Z group, such that the overall molar volume of thecopolymer is at least 150 mL/mole, also are within the scope of thepresent invention.

[0082] Finally, the Z group influences the chemical stability andmelting point of the monomer and resulting (co)polymer(s). Inparticular, we have found that any one of three types of substituents onthe ester portion of the acrylate are preferred: inclusion of an etheroxygen in an aliphatic or aromatic group; mixtures of positional isomersof aromatic substituents; and branched aliphatic moieties; as well ascombinations thereof.

[0083] As mentioned previously, Z can be one of four types of groups.First, Z can have the general formula —C(R_(f))₂E, wherein each R_(f)group and E are as defined above.

[0084] As to each R_(f), examples of potentially useful C₁-C₂₀ acyclicaliphatic groups include methyl, methoxymethyl, ethoxymethyl,propoxymethyl, butoxymethyl, ethyl, propyl, butyl, pentyl, hexyl,heptyl, octyl, nonyl, decyl, undecyl, dodecyl, methoxyethoxymethyl(i.e., CF₃OCF₂CF₂OCF₂), methoxypropoxymethyl, methoxyethoxyethoxymethyl,ethoxyethoxymethyl, ethoxyethyl, and methoxyethyl groups. For each alkylgroup named having more than two carbon atoms, isomers thereof,particularly branched isomers, are included in this definition. Further,all alkyl groups are fluoroalkyl, chloroalkyl, or fluorochloroalkylgroups; that is, all hydrogen atoms have been replaced by fluorineatoms, chlorine atoms, or combinations thereof.

[0085] Examples of potentially useful R_(f) groups comprising C₃-C₂₀cycloaliphatic groups include cyclopropyl, cyclobutyl, cyclopentyl,cyclohexyl, cycloheptyl, cyclooctyl, bicyclo{2.2.1 }hexyl,bicyclo{2.2.2}octyl, bicyclo{3.2.2}nonyl, and bicyclo{4.4.0}decyl. Anyof the cycloaliphatic groups can include C₁-C₁₀ straight-chain orbranched aliphatic carbon substituents, as well as above-named acylicaliphatic groups, at any position thereof, consistent with steric bulkconsiderations. As noted, all hydrogen atoms of the cycloaliphaticgroups are to be replaced by fluorine atoms, chlorine atoms, orcombinations thereof.

[0086] Examples of R_(f) groups as potentially useful C₆-C₂₀ aryl groupsinclude phenyl, naphthyl, indenyl, biphenyl, anthracyl, phenanthryl, andfluorenyl groups, wherein all hydrogen atoms have been replaced byfluorine atoms, chlorine atoms, bromine atoms, or combinations thereof.

[0087] Examples of R_(f) groups as potentially useful C₇-C₂₀ alkarylgroups include methylphenyl, ethylphenyl, methylnaphthyl,dimethylphenyl, indanyl, and butylphenyl groups, wherein all hydrogenatoms have been replaced by fluorine atoms, chlorine atoms, bromineatoms, or combinations thereof.

[0088] Examples of R_(f) groups as potentially useful C₇-C₂₀ aralkylgroups include phenethyl and benzyl groups, wherein all hydrogen atomshave been replaced by fluorine atoms, chlorine atoms, bromine atoms, orcombinations thereof.

[0089] Examples of potentially useful R_(f) groups comprising C₄-C₂₀heteroaryl, heteroaralkyl and heteroalkaryl groups include any cyclicaromatics comprising at least one oxygen, nitrogen or sulfur atom in thering, including those having C₁-C₁₀ straight-chain or branched aliphaticcarbon substituents, as well as above-named acylic aliphatic groups, atany position thereof, consistent with steric bulk considerations. Usefulheteroaromatics include furan, thiophene, pyrrole, 1,2- and 1,4-pyran,1,2- and 1,4-thiopyran, pyridine, oxazole, isoxazole, thiazole,isothiazole, imidazole, pyrazole, 1,2,3- and 1,2,4-triazole, tetrazole,pyridazine, pyrimidine, pyrazine, 1,4-dioxin, 1,4-dithiin, 1,2-, 1,3-,and 1,4-oxathiin, 1,2-, 1,3-, and 1,4-oxazine, and 1,2-, 1,3-, and1,4-thiazine. It is to be appreciated that all hydrogen atoms of each ofthe above-named heteroaryl ring systems and their alkyl-substitutedanalogs are to replaced by fluorine atoms, chlorine atoms, bromineatoms, or combinations thereof.

[0090] In addition to the single-ring heteroaryl, heteroaralkyl andheteroalkaryl groups, R_(f) groups can comprise analogous fused-ringheteroaromatic compounds including benzofuran, thionaphthene, indole,isothionaphthene, isobenzofuran, isoindole, 1,2- and 1,4-benzopyran,1,2- and 1,4-benzothiopyran, quinoline, isoquinoline, cinnoline,quinazoline, quinoxaline, phthalazine, benzoxazole, benzothiazole,benzimidazole, benzpyrazole, benzotriazole, and numerous fused ringgroups comprising three or more rings comprising at least one N-, O-, orS-atom, including any of these having C₁-C₁₀ straight-chain or branchedaliphatic carbon substituents, as well as above-named acylic aliphaticgroups, at any position thereof, consistent with steric bulkconsiderations. It is to be appreciated that all hydrogen atoms of eachof the above-named heteroaryl ring systems and their alkyl-substitutedanalogs are to replaced by fluorine atoms, chlorine atoms, bromineatoms, or combinations thereof.

[0091] Some R_(f) groups that can be particularly useful for certainapplications include methyl, chloromethyl, ethoxymethyl,(2-chloroethoxy)methyl, trichloroethoxymethyl, hexyl, cyclohexyl, andbutoxymethyl.

[0092] R_(f) groups including branched aliphatic or alkyl groups may bepreferred when mixtures of branched isomers or stereoisomers can beobtained that result in lowering of the haloacrylate melting point toprovide ease of handling of the monomers.

[0093] E represents one of four substituents. Specifically, E can beR_(f),

[0094] wherein R¹, R², R_(f), and Q are defined as above. In a preferredembodiment, each R¹ or R² is F.

[0095] Z also can have any of the formulae

[0096] in which each R¹ is defined as above. Where Z has this formula,preferred compounds include those where each R¹ is either F or Cl.

[0097] Third, Z also can have the formula

[0098] wherein each R² is as previously defined.

[0099] In a preferred embodiment, at least one R² is F, OC₆F₅, SC₆F₄CF₃,OC(O)C₆F₅, or OSO₂C₄F₉.

[0100] Fourth, Z can have the formula CR_(f)(E)₂ wherein each E andR_(f) are as previously defined.

[0101] Some preferred halogenated acrylates of the present inventionhaving homopolymers with refractive indices greater than or equal to1.457 (i.e., “high index materials”) are represented by the followingformulae:

[0102] Some preferred halogenated acrylates of the present inventionhaving homopolymers with refractive indices less than 1.457 (i.e., “lowindex materials”) are represented by the following formulae:

[0103] In addition to the acrylate monomers shown above, the followingtertiary carbinols can easily be converted into the correspondingacrylates, the homopolymers of which are predicted to be low indexmaterials:

[0104] In the above formulae,

[0105] represents a cyclohexyl ring in which all hydrogen atoms arereplaced by fluorine atoms (i.e., a perfluorocyclohexyl group).

[0106] Many preferred halogenated acrylate monomers of the inventioninclude at least one perfluoroether moiety. An ether linkage allowsready variation of the structure of a starting material to befluorinated and of the fluorinated product. It has been found that theperfluoroether group provides favorable physical properties, such as lowmelting point or liquidity at 23° C., while allowing control of therefractive index of the corresponding homopolymer and related copolymersby control of structure and substituents.

[0107] Homopolymers prepared from these acrylates have characteristicindices of refraction. Accordingly, one wishing to use one or more ofthese compounds (or any of the halogenated acrylates of the presentinvention) can choose as halogenated acrylate the homopolymer of whichhas an index of refraction that matches that which is desired or canchoose two or more of these acrylate monomers and copolymerize them soas to provide a polymer that has the desired index of refraction.

[0108]FIG. 1 shows absorption versus wavelength plots for threehalogenated polyacrylates: poly(perfluorophenylacrylate) (PFPA)(comparative tracing C), poly(perfluorophenylthioacrylate)(PFPTA)(comparative tracing B), and compound VIII of the presentinvention (tracing A), above. PFPA is commercially available fromPolysciences, Inc. (Warrington, Pa.) whereas PFPTA and compound VIII canbe prepared by, for example, reaction of acryloyl chloride withpentafluorothiophenol or 2-(pentafluorophenyl)-2-perfluorooctanol,respectively. The aforementioned wavelength regions of interest as wellas the acceptable absorption limits in those wavelength regions (imposedby the aforementioned Bellcore specifications) are represented by boxesD and E. As is apparent, all three of the polyacrylates have acceptable(i.e., very low) absorption in the 1310 nm region, but only compoundVIII has a completely acceptable absorption profile in the 1550 nmregion.

[0109] Halogenated acrylates of the present invention can be prepared byreacting an acrylic acid derivative such as acryloyl chloride or acrylicanhydride with a perhalogenated alcohol, alkoxide, or alkoxy-substitutedalcohol in the presence of an organic base (e.g., a tertiary amine).Using 2-acryloyloxyheptafluoronaphthalene (compound V) as an example,one can react heptafluoro-2-naphthol with acryloyl chloride andtriethylamine in an appropriate solvent such as acetonitrile. (SeeExample 1, below, for more details.) Choice of solvent(s), temperature,pressure, and other reaction variables are within the level of skillpossessed by the ordinarily skilled artisan discussed below.

[0110] Perhalogenated alkoxides may be prepared from the correspondingperhalogenated alcohols by treatment with base, or by treatment of aperhalogenated carbonyl compound with an alkali metal fluoride (e.g. KF)or perhalogenated carbanion sources such as organometallic reagents(e.g., organo lithiums or Grignard reagents). Perhalogenated alcohols orcarbonyl compounds may be prepared by the following methods:

[0111] 1) Addition of a perhalogenated organometallic compound to aperhalogenated ketone (e.g. C₆F₅MgCl+R⁶ _(f)COR⁶ _(f)→→R⁶ _(f)R⁶_(f)C₆F₅COH, where each R⁶ _(f) group independently can be aperhalogenated straight-chain, branched, or cyclic aliphatic groupcontaining from 1 to 20 carbon atoms and may contain up to 5 etheroxygen atoms). The perhalogenated ketone may be prepared by similaraddition of a perhalogenated organometallic compound to a perhalogenatedacid fluoride, or may be prepared by direct fluorination of an ester ofa secondary alcohol followed by cleavage of the resulting perhalogenatedsecondary ester.

[0112] 2) Displacement of a fluorine atom by a hydroxy (or latenthydroxy) on a perhalogenated arene compound.

[0113] A preferred class of perhalogenated alcohols or ketones isether-containing perhalogenated alcohols or ketones. These may beprepared by direct fluorination of an ether-containing precursor esterof a primary or secondary alcohol. For example, they may be prepared byreaction of an alcohol and either propylene glycol (Scheme 1) orepichlorohydrin (Scheme 2) to produce a secondary alcohol, which maythen be acylated, fluorinated by direct fluorination, and the resultingperhalogenated ester cleaved by any of the methods described in U.S.Pat. No. 5,466,877, incorporated herein by reference. Perfluorinatedketones of the structure R⁷ _(f)OCF₂COCF₃, R⁷ _(f)OCFCOCF₂Cl, and R⁷_(f)OCF₂COCF₂OR⁷ _(f) are novel where R⁷ _(f) is a linear perfluoroalkylor perfluorooxyalkyl group having from two to twenty carbon atoms. Thesecompounds are especially useful in preparing the acrylates of thisinvention to impart a low Tg and high molar volumes.

[0114] wherein R⁷ is a linear alkyl or oxyalkyl group which can beterminated by any of —CH₃, —CH(CH₃)₂, —C(CH₃)₃, —OCH₃—OCH(CH₃)₂, or—OC(CH₃)₃, wherein each R⁷ _(f) is the perhalogenated analog of R⁷, R⁷and R⁷ _(f) groups having from 1 to 20 carbon atoms, and Y can be Cl,OR⁷ and Y_(f) can be Cl or OR⁷ _(f). Preferred classes of theperfluorinated ether ketone intermediates are those mono- and diethersin which R⁷ _(f) is a perfluoro or per(chlorofluoro)alkyl group of 2-12carbons and containing up to 5 ether oxygens. Similarly, directfluorination of the di- or tri-esters can lead to di- or tri-ketones.

[0115] Halogenated acrylates containing bromine or chlorine in additionto fluorine are useful in increasing the refractive index of thecorresponding homo-and co-polymers. Chlorofluoroalkyl acrylates may beprepared by the previously described methods from eitherchlorofluoroketones or chlorofluoroacyl halides. See Example 24. Higheramounts of chlorine in the acrylate are especially useful in raising therefractive index. Surprisingly, it has been found that1,1-dichloroethoxy ethers and 1,1,1-trichloroethoxy ethers, whensubjected to direct fluorination, undergo a rearrangement to produce1,2-dichloro-perfluoroethoxy ethers and 1,1,2-trichloro-perfluoroethoxyethers respectively. See Examples 11 and 21, and Table 4, compounds 4-2,4-3, and 4-22. This rearrangement is illustrated in one embodiment, asfollows:

Cl₂CHCH₂OR⁸→ClCF₂CFClOR⁸ _(f),

[0116] and

Cl₃CCH₂OR⁸→Cl₂CFCFClOR⁸ _(f),

[0117] wherein R⁸ is a C₁-C₂₀ alkyl- or acyl-containing group optionallycontaining up to 5 ether oxygen atoms and R⁸ _(f) is the correspondingperhaloalkyl or perhaloacyl-containing group, optionally containing upto 5 ether oxygen atoms. Perhaloalkyl or perhaloacyl-containing esterscan be cleaved to produce perhaloketones and perhaloacid fluorides aspreviously described.

[0118] Preferred compounds have the formulae ClCF₂CFClOR⁸ _(f) andCl₂CFCFClOR⁸ _(f) and are made by direct fluorination of compounds ofthe formulae Cl₂CHCH₂OR⁸ and Cl₃CCH₂OR⁸, respectively, wherein R⁸ can bea C₁-C₂₀ alkyl- or acyl-group optionally containing up to 5 ether oxygenatoms and R⁸ _(f) can be the corresponding perfluoroalkyl orperfluoroacyl-containing group, optionally containing up to 5 etheroxygen atoms.

[0119] The rearrangement is surprising in view of the known instabilityof α-chloro ethers (see Adcock, et al., U.S. Govt. Report #AD139958(1984)). These 1,2-dichloroperfluoroethyl ethers and1,1,2-trichloroperfluoroethyl ethers are useful as solvents and in thepreparation of perfluoro- and chloroperfluorovinyl ethers (see U.S. Pat.No. 5,350,497). A preferred subset of these 1,2-dichloroperfluoro/per(chlorofluoro) ethers is that in which the R⁸ _(f) groupcontains 1 to 12 carbon atoms and up to 5 ether oxygen atoms. Anotherpreferred subset is that in which the preferred R⁸ _(f) group alsocontains a COF or SO₂F group.

[0120] Refractive index and optical absorbance data for several of thecompounds whose structures are shown above are given in Table 1, below.TABLE 1 Homopolymer Homopolymer Homo- Homo- average abs/cm¹ abs/cm >0.01² polymer polymer 1260- 1480- 1260- 1480- Cpd Example n_(1.31)n_(1.31) calc 1360 nm 1580 nm 1360 nm 1580 nm I 6 1.515 1.523 .004 .0121350-1360 1480-1580 IV 2 1.488 1.465 — — — — V 1 1.523 1.487 .006 .0121343-1360 1480-1580 VI 5 1.547 1.550 .003 .005 1350-1360 1480-1485 VII 41.465 1.452 .002 .008 1352-1360 1480-1500 VIII 22 1.380 1.348 .003 .0061357-1360 none IX 9 1.444 1.405 — — — — X 3 1.424 1.386 .006 .061350-1360 1480-1580 XI 7 1.418 1.386 .004 .002 1340-1360 none XII 151.368 1.331 — — — — XIII 8 1.446 1.421 .003 .003 1345-1360 none 10 1.5031.492 .006 .007 1348-1360 1480-1500 11 1.441 1.425 .003 .003 1355-1360none

[0121] The data of Table 1 show that a number of candidate haloacrylateshave acceptably low absorbances in the target wavelength regions. Inaddition, these data show that homopolymer refractive index calculations(W. Groh and A. Zimmermann, Macromolecules, 24, (December, 1991), p.6660) cannot predict the observed refractive index, particularly inlight of a need to predict refractive index with accuracy in the thirddecimal point.

[0122] As mentioned previously, the halogenated acrylates of the presentinvention are relatively easy to polymerize. Like most acrylates, theyare free radically polymerizable, often in less-than-rigorousconditions. In other words, although oxygen normally must be excludedfrom the area where an acrylate polymerization is performed, othermaterials (e.g., water) need not be so excluded.

[0123] As with most acrylates, the free radical polymerization of thehalogenated acrylates of the present invention can be initiated by heator by light, optionally but preferably in the presence of a thermal orphoto initiator, respectively. Of these two types of initiation,photoinitiation, particularly UV-type photoinitiation, is preferred. Inchoosing an initiator, consideration of the aforementioned optical lossgoals should be considered. For instance, certain UV initiators arehighly absorptive in near infrared wavelengths. One UV initiator thathas not proven to be especially absorptive in the wavelengths ofinterest is 2,2-diethoxyacetophene, Ph—C(O)CH(OCH₂CH₃)₂, wherein Ph isphenyl, hereinafter referred to as DEAP.

[0124] As with synthesis details discussed previously, choice ofsolvent(s), temperature, pressure, and other polymerization conditionsare within the level of skill possessed by the ordinarily skilledartisan. Nevertheless, further details on similar polymerizations can befound at, for example, S. R. Sandier and W. Karo in Polymer Syntheses,Vol. 1, 2nd Ed., Ch. 10 (pp 317-376) Academic Press, Inc., New York(1992).

[0125] Optionally, halogenated acrylate polymers of the invention may becrosslinked. Physical property changes achieved by crosslinking acrylatepolymers include elevated Tg, increased strength, reduced swelling whenexposed to solvent or other small molecules, and reduced flexibility.All of these may be highly desirable in achieving the “BellcoreSpecifications” requirements for optical branching components preparedfrom acrylates of this invention. Typical acrylate crosslinkers have C—Hbonds in addition to those in the acrylate functionality and maydetrimentally affect optical absorbances in the important 1260 to 1360nm and 1480 to 1580 nm wavelength regions (supra). Thus, there is a needfor polyfunctional acrylate crosslinkers with fewer C—H bonds in themolecule, preferably with CH only in the acryloyl group and on thea-carbon atoms of the polyol moiety, more preferably limiting the C—Hbonds to only those of the acrylate groups (i.e., no other C—H bonds inthe molecule). In an optical device, the crosslinker may be present at arelatively minor component and, as such, a higher hydrogen content canbe tolerated. Acrylates prepared from perhalogenated aromatic polyolsfit this criterion. Illustrative examples of these polyfunctionalacrylates include tetrafluorohydroquinone diacrylate (XX),tetrafluororesorcinol diacrylate (XXI), and octafluoro-4,4′-biphenoldiacrylate (XXII). Acrylates of other halogenated (chlorinated orbrominated) aromatic polyols may also be useful as crosslinkers of thisinvention. The corresponding polyfunctional homologous methacrylatecrosslinkers may be substituted for any of the acrylate crosslinkersnoted herein.

[0126] A number of brominated aromatic polyols may be readily purchasedor can be synthesized, e.g., by the reaction of bromine with an aromaticpolyol as is known in the art. Reaction of the brominated aromaticpolyol with, for example, acryloyl chloride in the presence of a basesuch as triethylamine provides the desired acrylates of the brominatedaromatic polyols. Illustrative examples of acrylated perhalogenatedaromatic polyols include tetrachlorohydroquinone diacrylate,tetrabromocatechol diacrylate (XXIII), tetrachlorocatechol diacrylate,tetrabromoresorcinol diacrylate, tetrachlororesorcinol diacrylate,tribromophloroglucinol triacrylate (XXIV), tribromopyrrogalloltriacrylate (XXV), and tribromo-1,2,4-benzenetriol triacrylate (XXVI).

[0127] Tribromoresorcinol diacrylate and trichlororesorcinol diacrylatecan also be useful as crosslinkers. They may be useful in opticaldevices where the number of hydrogen atoms is less important.

[0128] Non-aromatic acyclic aliphatic halogenated polyol polyacrylatesmay also be useful as crosslinking agents in the invention.Polyacrylates can be prepared by, e.g., the reaction of a perhalogenatedpolyol with an acryloyl halide, preferably acryloyl chloride.Perhalogenated polyols can be prepared by the perfluorination of analiphatic hydrocarbon-polyols or a halogenated, preferably chlorinated,aliphatic polyol by known fluorination methods, such as directfluorination.

[0129] Acyclic aliphatic halogenated polyol polyacrylates can have thegeneral formula R⁹ _(f)(CR¹⁸R_(f)OC(O)CH═CH₂)_(q), wherein R¹⁸ can be Hor F, R_(f) is as previously defined, q can be a whole number of 2 orgreater, preferably from 2 to 6, more preferably from 2 to 4, and R⁹_(f) preferably is an acyclic aliphatic halogenated group, free ofethylenic or other carbon-carbon unsaturation, having at least 1 carbonatom and optionally can comprise up to 50, preferably up to 10,non-carbon atoms such as oxygen, nitrogen, and sulfur in the aliphaticchain. R⁹ _(f) can comprise an oligomeric polyether, oligomericpolyamine, oligomeric polythiol or polyetheramine, such that the totalnumber of atoms in the R⁹ _(f) chain (i.e., the combination of carbonatoms and linking oxygen, nitrogen or sulfur atoms) can be up to 150,preferably up to 50, more preferably up to 25, and most preferably nomore than 20. Halogen atoms comprising the R⁹ _(f) group can befluorine, chlorine or bromine, preferably fluorine or chlorine, morepreferably a combination of fluorine and chlorine, and most preferablyexclusively fluorine.

[0130] Representative acyclic aliphatic halogenated polyol polyacrylatesare represented by the following formulae of fluorinated acrylates:

CF₃CH(OC(O)CH═CH₂)CF₂O(CF₂)₄OCF₂CH(OC(O)CH═CH₂)CF₃  XXVII

CF₃CF(OC(O)CH═CH₂)CF₂OCF₂CF(OC(O)CH═CH₂)CF₂OCF₂CF(OC(O)CH═CH₂)CF₃  XXVIII

[0131] Halogenated acrylates of the present invention are useful in thepreparation of polymers wherein the refractive index and the opticalloss of the polymer must be carefully controlled. Polymers andcopolymers prepared from the monomers find use in the manufacture ofoptical devices such as splitters, couplers, light guides, andwaveguides. In addition, (co)polymers of the present invention find useas adhesives and index matching compounds for joining optical elementssuch as lenses, mirrors, optical fibers, light guides, and waveguides.(Co)polymers of the invention find further use as cladding and/orprotective materials for optical devices such as those named above aswell as optical fibers.

[0132] In addition to the aforementioned utilities, the inventivemonomers and polymers are useful in a variety of applications such asflame retardants, protective coatings, and adhesives. Acrylates frombrominated aromatic polyols can have utility in raising the refractiveindex of any acrylate system requiring crosslinking and/or flameresistance.

[0133] Objects and advantages of this invention are further illustratedby the following examples. The particular materials and amounts thereof,as well as other conditions and details, recited in these examplesshould not be used to unduly limit this invention.

EXAMPLES

[0134] Unless otherwise noted, all materials are commercially availablefrom Aldrich Chemical Co. (Milwaukee, Wis.). “Room temperature” or“ambient temperature” means about 21° C. All chemical structuressynthesized were confirmed by spectroscopic analysis.

[0135] Test Methods

[0136] Glass Transition Temperature (Tg)

[0137] Polymer films were prepared from liquified monomers (or monomermixtures) that were doped with 0.2-0.5% by weight, based upon the totalweight of polymerizable monomer(s), of a photoinitiator, preferablyPhC(O)CH(OCH₂CH₃)₂ (DEAP), syringe-filtered, deoxygenated, placedbetween two silicon-treated polyethylene terephthalate (PET) releaseliners and exposed to ultra-violet radiation from an Oriel 50 wattmercury arc lamp (Oriel Corp., Stratford, Conn.) or a SylvaniaBlacklight fluorescent bulb (Sylvania 350 BL bulb, Siemens Corp./OsramSylvania Inc., Danvers, Conn.) for 30-60 minutes at approximately 23° C.The polymeric films were further heated at 60-70° C. for approximately30 minutes, then baked at 120° C. in an oven for several hours to ensurecomplete cure. The release liners were removed and the films were driedin a forced-air oven at 105° C. for at least 4 hours but not longer than10 hours. The glass transition temperature (Tg) of each sample wasdetermined by Differential Scanning Calorimetry using a Perkin-Elmer7-Series Thermal Analysis System (Perkin-Elmer Corp., Norwalk, Conn.)with a general temperature range of −50 to 200° C. Tg values weredetermined according to ASTM protocol E1356-91 except a 20° C./minuteramp was used. If a transition could not be found in the general range,the temperature range was expanded as needed. Measurements were madeafter two heat and cool cycles. The Tg was recorded as a midpointdetermination of the point at which the derivative of the interpolatedslope of the transition equaled zero.

[0138] Refractive Index (n_(λ))

[0139] The index of refraction was determined by inserting an opticalfiber capable of carrying light at the required wavelengthn_(λ)(typically, an 8 mW continuous wave laser diode at 1300 nm) into aliquid monomer or mixture of monomers, polymerizing the monomer(s) asdescribed above to obtain a polymer, and measuring the intensity of theback reflection from the interface of the fiber and the sample. This wascompared to the intensity of back-reflection when the same fiber wasimmersed in a material of known index (water) at the probing wavelength.Using the value of the refractive index of the fiber itself, the indexof the probed material was calculated. Solid materials were first meltedand the fiber inserted. In order to increase sensitivity of themeasurements, the intensity of the incident light was modulated with asquare-wave generator from a function generator (HP 8013A PulseGenerator, Hewlett Packard Instruments, Palo Alto, Calif.) and thedetected signal analyzed using a lock-in detector (Stanford ResearchSystems Model SR510 Lock-In Amplifier, Stanford Research Systems Inc.,Sunnyvale, Calif.) which was given the same square-wave referencesignal. The refractive index measurements were reproducible to ±0.0015.

[0140] Optical Absorbance

[0141] Absorbance measurements were made on polymerized cylindricalplugs of sample. The plug typically had a diameter of 0.5 cm and heightof 1 cm. Liquefied monomer was doped with 0.2% by weight DEAP, filtered,deoxygenated, and placed in a plastic mold prior to polymerization.Polymerization was effected by exposure to a UV lamp, typically OrielModel 6281, for 30 minutes followed by heat annealing at 60-80° C. underUV light for an additional time of from 30 minutes to several hours inorder to complete the polymerization reaction. Absorbance of the plugswas measured using a UV spectrometer (Model UV-3101PC, ShimadzuScientific Instruments, Inc., Columbia, Md.) equipped with anintegrating sphere. To correct for the loss of probe light intensity dueto reflection and scattering from the surface of the plug, which wouldbe measured as an absorption loss, a baseline absorption (the lossrecorded at 1050-1070 nm) was subtracted from the entire spectrum.

Example 1 Heptafluoronaphthyl Acrylate (Compound V)

[0142] For about 3.5 hours, a mixture of 25 g octafluoronaphthalene (PCRInc.; Gainesville, Fla.), 12 g KOH, and 100 mL tertiary butyl alcoholwas refluxed. Water was added, and the tertiary butyl alcohol wasdistilled from the reaction mixture. The residue remaining in the flaskwas acidified with HCl and the aqueous mixture was extracted three timeswith 75 mL dichloromethane. The combined extracts were washed twice with150 mL distilled water, dried over MgSO₄, and rotary evaporated to yielda semi-crystalline solid. Recrystallization from hot hexanes gave 18 gheptafluoro-2-naphthol (72% yield) as slightly tan colored crystals.

[0143] In 150 mL acetonitrile, 15 g heptafluoro-2-naphthol was dissolvedand cooled to 0° C. before 12 mL triethylamine and 7 mL acryloylchloride, sequentially, were added slowly by syringe. This resulted inthe formation of a light colored precipitate. The reaction was stirredfor about two hours at 0° C. and about two hours at room temperature,then poured onto ice and allowed to warm to room temperature andextracted three times with 40 mL dichloromethane. The combined extractswere washed twice with 100 mL distilled water, dried over MgSO₄, androtary evaporated to yield a reddish orange colored oil. Vacuumdistillation (75-78° C., 67 Pa) gave 16.3 g (90% yield) of2-acryloyloxyheptafluoronaphthalene (compound V) as a colorless liquid.A homopolymer prepared as described in Example 13, below, from theacrylate had a refractive index n_(1.31) of 1.523, and average abs/cm of0.006 (1260-1360 nm) and average abs/cm of 0.12 (1480-1580 nm).

Example 21-Pentafluorophenyl-1-pentachlorophenyl-1-acryloyloxyheptafluoroethylether(Compound IV)

[0144] Hexachlorobenzene (35 g) was slurried in 160 ml of anhydrousethyl ether at −40° C. A 2.5 M hexanes solution of n-butyllithium (54.1mL) was added, and the reaction was stirred for 30 minutes at −40° C.Perfluoro-2-ethoxyacetylfluoride (40 g, 72% pure, prepared from2-ethoxyethyl acetate by the method described in Example 1 of U.S. Pat.No. 5,326,919, incorporated herein by reference) was added to the −40°C. reaction mixture which was then allowed to warm slowly to roomtemperature. The reaction mixture was quenched with 200 mL of cold 5%aqueous HCl. The aqueous mixture was extracted with ethyl ether and theextracts were dried over MgSO₄ and rotary evaporated to givepentachlorophenyl perfluoroethoxymethyl ketone (49% crude yield). Vacuumdistillation (105-109° C., 240 Pa) using a 15 cm Vigreux column gave19.7 g of a colorless liquid which slowly crystallized on standing.

[0145] About 2.1 g magnesium metal turnings (J. T. Baker Inc.;Phillipsburg, N.J.) were dried by heating under a nitrogen purge,cooled, and suspended in 50 mL of anhydrous ethyl ether in a nitrogenatmosphere. A mixture of 8.4 g of chloropentafluorobenzene and 8.1 g ofdibromoethane was added dropwise to the suspension. The reaction mixturewas stirred at a temperature below 30° C. for 95 minutes in an ice bath.Pentachlorophenyl perfluoroethoxymethyl ketone (19.4 g) dissolved in 20mL of ethyl ether was added and approximately one half of the ethylether was distilled from the reaction flask. Anhydrous 2-methoxyethylether (50 mL) was added, and the reaction mixture was heated to 75° C.for one hour. The reaction was quenched with 150 mL of 10% aqueous HCl,extracted with dichloromethane, and the extracts were dried over MgSO₄and rotary evaporated to an oil. Chromatography on a 5×35 cm silica gelcolumn (230-400 mesh, 60 Å) using 4:1 hexane:toluene as the elutionsolvent gave 15.1 g (61% yield) of 99.9% pure1-pentafluorophenyl(1-pentachlorophenyl)(2-pentafluoroethoxy)difluoroethanolas a colorless hard wax.

[0146] A 14.8 g sample of1-pentafluorophenyl(1-pentachlorophenyl)(2-pentafluoroethoxy)difluoroethanolin 150 mL of dichloromethane was cooled to 5° C. under a dry nitrogenatmosphere. Acryloyl chloride (2.1 mL) was added, followed by dropwiseaddition of dry, distilled triethylamine (3.6 mL, J. T. Baker). Thereaction mixture was refluxed for 90 minutes, cooled to roomtemperature, stirred for 14 hours, and quenched with 250 mL of water.The organic layer was collected and rotary evaporated to give a yellowoil. Chromatography on a 5×40 cm silica gel column (230-400 mesh, 60 Å)using 8:1 hexane-ethyl acetate as the eluting solvent gave 12.9 g (80%yield) of1-pentafluorophenyl-1-pentachlorophenyl-1-acryloyloxyheptafluoro-ethylether(compound IV) as a colorless liquid.

Example 31-Acryloyoxy-1,1-bis(pentafluorophenyl)-2-(2-pentafluoroethoxytetrafluoroethoxy)difluoroethane(Compound X)

[0147] About 9.7 g magnesium metal turnings were dried by heating undera nitrogen purge, cooled, and suspended in 250 mL anhydrous ethyl etherin a dry nitrogen atmosphere. A mixture of 40.5 gchloropentafluorobenzene and 37.6 g dibromoethane was added dropwise tothe suspension and the reaction mixture was stirred for one hour at lessthan 30° C. in an ice bath. About 34.8 gperfluoro-2-(2-ethoxyethoxy)acetylfluoride, prepared by directfluorination of di(ethylene glycol) ethyl ether acetate as described inthe previously incorporated Example 1 of U.S. Pat. No. 5,326,919, wasadded dropwise, and the reaction was stirred at room temperature for 18hours. The reaction was quenched with dilute aqueous HCl and extractedwith dichloromethane. After drying over MgSO₄, the solvent was removedby rotary evaporation and the residue was vacuum distilled (136-138° C.,1330 Pa) to give 44.2 g (36% yield) of1,1-bis(pentafluorophenyl)-2-(2-pentafluoroethoxytetrafluoroethoxy)difluoroethanolas a pale yellow liquid.

[0148] A 15.4 g sample of1,1-bis(pentafluorophenyl)-2-(2-pentafluoroethoxytetrafluoroethoxy)difluoroethanolin 50 mL dichloromethane was cooled to 5° C. under an atmosphere of drynitrogen. Acryloyl chloride (2.05 mL) was added followed by the dropwiseaddition of 3.5 mL dry, distilled triethylamine. The reaction mixturewas refluxed for one hour and an additional 0.35 mL acryloyl chlorideand 0.35 mL triethylamine were added. After an additional hour ofreflux, the reaction was quenched with water and the organic layer wascollected and rotary evaporated to give a pale yellow oil.Chromatography on a 5×40 cm silica gel column (230-400 mesh, 60 Å) using12:1 hexane-ethyl acetate as the eluting solvent gave 14.4 g1-acryloyoxy-1,1-bis(pentafluorophenyl)-2-(2-pentafluoroethoxytetrafluoroethoxy)difluoroethane(88% yield) (compound X) as a colorless liquid.

Example 4 5-Pentafluorophenoxy-3,4,6-trifluoro-2-trifluoromethylphenylacrylate (Compound VII)

[0149] A mixture of 98.4 g pentafluorophenol, 0.1 g sodium saccharin,and 120 mL hexamethyldisilazane was stirred at 73° C. for 17 hours afterthe initial vigorous reaction. Distillation at 160-61° C. using a 15 cmVigreux column yielded 119.3 g, 87% ofpentafluorophenoxytrimethylsilane, C₆F₅OSi(CH₃)₃.

[0150] A 56.2 g sample of pentafluorophenoxytrimethylsilane was mixedwith 50.0 g octafluorotoluene, 3.0 g anhydrous CsF (Acros Organics:Pittsburgh, Pa.) and 100 mL anhydrous acetonitrile under nitrogen andstirred at reflux. The reaction was followed by GLC for 4 days, withaddition of 3.4 g additional hexamethyldisilazane to reconvert traces ofpentafluorophenol to the silyl derivative. The mixture was quenched inwater, extracted with diethyl ether, dried over MgSO₄, and concentratedon a rotary evaporator. The oily residue was distilled (80-100° C., 107Pa) to give 74.7 g (88% yield) of 4-trifluoromethylnonafluorodiphenylether, C₆F₅OC₆F₄-4-CF₃, and minor amounts of positional isomers thereof.

[0151] All of the product from the previous paragraph was mixed with14.7 g 85% KOH in 250 mL t-butanol, and the mixture was refluxed for 17hours. The reaction mixture was quenched with dilute aqueous HCl,extracted with CH₂Cl₂, dried over MgSO₄, and the extracts concentratedon a rotary evaporator. The product was vacuum distilled (97-120° C., 40Pa) to give 47.8 g (64%) of a mixture of isomers of2-hydroxy-4-pentafluorophenoxyhexafluorotoluene.

[0152] The isomeric mixture (47.8 g) was mixed with 12.5 mL acryloylchloride in 200 mL cold methylene chloride and treated with 20 mLtriethylamine dropwise. The mixture was stirred for 17 hours, filtered,and the filtrate was concentrated on a rotary evaporator. The residuewas extracted with ethyl ether and the extracts were filtered andconcentrated, and the residue was subjected to flash chromatography onabout 450 cm³ of silica gel. Elution with 2000 mL hexanes gave 40.7 gisomeric acryloyloxy-4-pentafluorophenoxyhexafluorotoluenes (75% yield)as a colorless liquid. Based on ¹⁹F-NMR analysis, the main isomer was2-acryloyloxy-4-pentafluorophenoxyhexafluorotoluene (compound VII).

Example 5 2,4,6-Trichlorodifluorophenyl Acrylate (Compound VI)

[0153] In a 2 L 3-neck round bottomed flask equipped with an overheadstirrer were placed 120 g (85% pure) KOH, 200 g1,3,5-trichlortrifluorobenzene (Oakwood Products, Inc.; West Columbia,S.C.), and 600 mL t-butanol. The mixture was stirred and refluxed for 4hours. Approximately 500 mL t-butanol was distilled from the reactionmixture. The flask was cooled to room temperature and 600 mLacetonitrile was added. The flask was further cooled in an ice bath and138 mL acryloyl chloride were added dropwise over the course of twohours. The reaction was stirred for an hour at 0° C. followed by twohours at room temperature. The reaction was then quenched with icewater, acidified with dilute HCl, and extracted with dichloromethane.The extracts were washed with saturated aqueous sodium bicarbonate anddistilled water, then dried over MgSO₄, filtered, and concentrated on arotary evaporator. The crude product was vacuum distilled (96-105° C.,13-130 Pa) to give 219 g 2,4,6-trichlorodifluorophenyl acrylate (89.7%yield) (compound VI) as a colorless liquid which crystallized onstanding.

Example 6 Bromotetrafluorophenyl Acrylate (Compound I)

[0154] As in Example 5, 120 g KOH, 110 mL bromopentafluorobenzene(Oakwood Products, Inc.), and 500 mL t-butanol were combined. Themixture was stirred and refluxed for 4 hours and then approximately 400mL t-butanol was distilled from the reaction mixture. The flask wascooled to room temperature and 500 mL acetonitrile was added. The flaskwas further cooled in an ice bath and 100 mL acryloyl chloride was addeddropwise over the course of an hour. The reaction was stirred for anhour at 0° C. followed by 16 hours at room temperature, then quenchedwith ice water, acidified with dilute HCl, and extracted withdichloromethane. The extracts were washed with saturated aqueous sodiumbicarbonate and distilled water, then dried over MgSO₄, filtered, andconcentrated on a rotary evaporator. The crude product was vacuumdistilled (98-102° C., 1600 Pa) to give 177 g (67% yield) of a mixtureof bromopentafluorophenyl acrylate isomers as a colorless liquid.Analysis by ¹⁹F NMR spectroscopy indicated that the major isomer waspara-bromopentafluorophenyl acrylate (compound I).

Example 7 1-Acryloyloxy-1-pentafluorophenylperfluorocyclohexane(Compound XI)

[0155] Under a nitrogen atmosphere, 60 g bromopentafluorobenzene in 200mL dry ether were added to 6.32 g magnesium at a rate that maintained asteady reflux. The reaction was stirred for one additional hour.Perfluorocyclohexanone (prepared, for example, as in U.S. Pat. No.3,321,515, Examples 65-68) (67.5 g) was added in one portion and thereaction allowed to stir for about 16 hours. The reaction mixture wasquenched with 200 mL of 10% HCl and extracted twice with 150 mL CH₂Cl₂.Drying of the CH₂Cl₂ layer (on MgSO₄) and rotary evaporation gave anoil. Vacuum distillation (82° C., 80 Pa) gave 74.5 g1-pentafluorophenylperfluorocyclohexanol (70% yield) as a colorlessliquid.

[0156] Under a N₂ atmosphere, 4.63 mL acryloyl chloride was added viasyringe to an ice-cold solution of 21.69 g1-pentafluorophenylperfluorocyclohexanol in 100 mL dry ether.Triethylamine was distilled from CaH₂ and 7.9 mL (56.3 mmol) was addedvia syringe. The reaction was stirred for 30 minutes in an ice-bath andstirred at room temperature for about 16 hours, then filtered and rotaryevaporated to give an oily solid. This was passed through a short pathsilica gel column with CH₂Cl₂ as the eluent to give an oil afterevaporation. Vacuum distillation (77-80° C., 67 Pa) gave 15.2 g (63%yield) of 1-acryloyloxy-1-pentafluorophenylperfluorocyclohexane(compound XI) as a colorless liquid.

Example 8: 1-Acryloyloxy-1-(3,5-dichloro-2,4,6-trifluorophenyl)perfluorocyclohexane (Compound XIII)

[0157] Under a N₂ atmosphere 29.5 g of1,3,5-trichloro-2,4,6-trifluorobenzene (Oakwood Products, Inc.) weredissolved in 150 mL dry ethyl ether. The solution was cooled to −78° C.in an acetone/dry-ice bath, then treated with 62.7 mL n-butyllithium (2M solution in hexanes) over a two-hour period. Stirring was continuedfor 3 hours at −78° C. Via syringe, 34.8 g perfluorocyclohexanone wereadded, and the mixture was stirred at room temperature for 16 hours. Thereaction was quenched with dilute HCl and extracted with ethyl ether,and the extracts were dried (using MgSO₄) and rotary evaporated. Vacuumdistillation (118-120° C., 80-110 Pa) gave 37.3 g1-(3,5-dichloro-2,4,6-trifluorophenyl) perfluorocyclohexanol (62% yield)as a colorless liquid.

[0158] Under a N₂ atmosphere, 4.43 mL acryloyl chloride were added viasyringe to an ice-cold solution of 20 g1-(3,5-dichloro-2,4,6-trifluorophenyl)perfluorocyclohexanol in 150 mLdry ethyl ether. Via syringe, 7.6 mL triethylamine (freshly distilledfrom CaH₂) was added, stirring was continued for 10 minutes in theice-bath, after which the reaction mixture was stirred at roomtemperature for about 18 hours. The reaction mixture was filtered andthe residue washed with petroleum ether. The filtrate and washes werecombined and rotary evaporated to give an oil that was vacuum distilled(112-119° C., 80 Pa) to give 12 g (54% yield) of1-acryloyl-1-(3,5-dichloro-2,4,6-trifluorophenyl)perfluorocyclohexane(compound XIII) as an oil that solidified on standing.

Example 92-Acryloyloxy-1-{(2-trifluoromethoxytetrafluoroethoxy)tetrafluoroethoxy}-2-pentachlorophenylpentafluoropropane(Compound IX)

[0159] Under a nitrogen atmosphere, 21.4 g hexachlorobenzene wassuspended in 200 mL dry ethyl ether and the reaction flask was cooled to−40° C. in an acetonitrile/dry-ice bath. A 1.6 M hexanes solution (47.1mL) of n-butyllithium was added by syringe and the reaction was stirredat −40° C. for two hours. A 35 g sample of1-{(2-trifluoromethoxytetrafluoroethoxy)tetrafluoroethoxy}pentafluoroacetone,prepared by the method as described in Example 23, below, was added inone portion and the reaction was allowed to come to room temperaturewhile stirring for about 16 hours). The reaction was quenched withdilute aqueous HCl and the mixture was extracted with ethyl ether. Theextract was dried (with MgSO₄) and rotary evaporated to give an oil.Vacuum distillation (133-135° C., 160 Pa) gave 10 g1-{(2-trifluoromethoxytetrafluoroethoxy)tetrafluoroethoxy}-2-pentachlorophenylpentafluoro-2-propanol(18% yield) as a colorless liquid.

[0160] Under an N₂ atmosphere, an ice-cold solution of 8.12 g of theabove perfluoro alcohol in 100 mL dry ethyl ether was treated with 1.03mL acryloyl chloride via syringe. Triethylamine (1.8 mL, distilled fromCaH₂) was added via syringe, and the reaction was stirred at roomtemperature for about 16 hours. The reaction mixture was filtered androtary evaporated to an oily solid. The oily solid was extracted withpetroleum ether and the extracts were concentrated to a viscous oil.This oil was vacuum distilled (140-143° C., 120 Pa) to give 5.5 g (63%yield) of2-acryloyloxy-1-{(2-trifluoromethoxytetrafluoroethoxy)tetrafluoro-ethoxy}-2-pentachlorophenylpentafluoropropane(compound IX) as a colorless oil.

Example 10 Acryloyloxychlorooctafluorodiphenyl Ether (Isomeric Mixture)

[0161] A mixture of 4.00 g pentafluorophenol, 4.00 gchloropentafluorobenzene, 0.12 g 18-crown-6 ether, 1.4 g powdered 85%KOH, and 15 mL diglyme was stirred at 130° C. for 18 hours. The cooledmixture was washed with water, extracted with methylene chloride, andthe extracts rotary evaporated to yield 4.6 g of a sticky solid. Vacuumdistillation (85-95° C., 33 Pa) of the combined residues from severalcondensations yielded 23.6 g of solid product that melted at 58-63° C.Analysis by GC/MS showed the solid to be a mixture of twochlorononafluorodiphenyl ether isomers.

[0162] The chlorononafluorodiphenyl ethers (23.4 g) were mixed with 8.4g of 85% KOH in 150 mL t-butanol and the mixture was refluxed for 17hours. The reaction mixture was quenched with dilute HCl, extracted withCH₂Cl₂, dried over MgSO₄, and concentrated on a rotary evaporator. Theproduct was vacuum distilled (35° C., 66 Pa) to give 19.6 g (84%) of amixture of seven chlorohydroxyoctafluorodiphenyl ether isomers whichwere confirmed by spectroscopic analysis.

[0163] The isomeric chlorohydroxyoctafluorodiphenyl ether mixture wasmixed with 6.0 mL acryloyl chloride in 250 mL cold methylene chlorideand 10 mL triethylamine was added dropwise. The mixture was stirred for17 hours, filtered, and the filtrate was rotary evaporated. The residue(27.1 g) was extracted with ethyl ether and the extracts were filteredand concentrated on a rotary evaporator. This residue was subjected toflash chromatography on about 450 cm³ of silica gel and eluted withhexanes to give 14.8 g (65% yield) of a mixture of seven isomers ofchloro(acryloyloxy)octafluorodiphenyl ether as a colorless liquidconfirmed by spectroscopic analysis.

Example 112-Acryloyloxy-2-pentafluorophenyl-3-(1,2,2-trichloro-1,2-difluoroethoxy)pentafluoropropane

[0164] An ethereal solution of pentafluorophenyl magnesium bromide wasprepared under a N₂ atmosphere by the addition of 1 mL of a solution of12.9 g bromopentafluorobenzene in 20 mL ethyl ether to 1.3 g magnesium.An exothermic reaction ensued and the remaining bromopentafluorobenzenesolution was added at such a rate as to maintain a steady reflux. Thesolution was stirred for an additional 45 minutes, then treated with16.7 g 1-(1,2,2-trichloro-1,2-difluoroethoxy)perfluoroacetone (84%pure), prepared as described in Example 21, below, and the mixture wasstirred at room temperature for 72 hours. The reaction was quenched with200 mL of 10% aqueous HCl and extracted with 150 mL dichloromethane. Theextract was dried over MgSO₄ and concentrated to an oil by rotaryevaporation. Vacuum distillation (75-80° C., 67 Pa) of the oil gave 14 g2-pentafluorophenyl-3-(1,2,2-trichloro-1,2-difluoroethoxy)pentafluoro-2-propanol(55% yield) as a colorless liquid.

[0165] A 12.2 g sample of the propanol prepared above was dissolved in50 mL dry ethyl ether under a nitrogen atmosphere and the solution wascooled in an ice bath. Acryloyl chloride (2.4 mL) was added by syringe.Triethylamine (3.0 g), distilled from CaH₂, was then added by syringeand the reaction was stirred for 30 minutes at 0° C. The ice bath wasremoved and the reaction was stirred for an additional 2 hours. Thereaction was filtered and the filtrate was washed twice with 25 mLwater, then dried over MgSO₄ and rotary evaporated to an oily solid. Thesolid was dissolved in dichloromethane and filtered through silica geland the filtrate was rotary evaporated to an oil. The oil was vacuumdistilled (100-105° C., 67 Pa) to give2-acryloyloxy-2-pentafluorophenyl-3-(1,2,2-trichloro-1,2-difluoroethoxy)pentafluoropropane (5.85 g, 43% yield) as a colorlessliquid.

Example 12 1,2-bis(acryloyloxy)tetrabromobenzene (Compound XXIII)

[0166] Tetrabromocatechol (25 g) was dissolved in 250 mL acetonitrileand the solution was cooled to 0° C. in an ice bath. Triethylamine (17mL) was added and the mixture was stirred at 0° C. for two hours.Acryloyl chloride (10 mL) was added dropwise by syringe, the ice bathwas removed, and the reaction was stirred for 16 hours. The reaction wasquenched with ice water and was acidified with dilute aqueous HCl togive a cream colored precipitate. The precipitate was collected byfiltration and washed with water. Crystallization from hot methanol gave20.6 g 1,2-bis(acryloyloxy)tetrabromobenzene (66% yield) as fine,colorless needles. The product had a melting point of 135-37° C.

Example 13 Preparation of Polymers

[0167] To prepare polymers useful in the invention, liquidified monomers(or monomer mixtures) were doped with 0.2-0.5% by weight, based upon thetotal weight of polymerizable monomer(s), of a photoinitiator,preferably PhC(O)CH(OCH₂CH₃)₂ (DEAP), syringe-filtered, deoxygenated andexposed to UV radiation from an Oriel™ 50 watt mercury arc lamp or aSylvania Blacklight fluorescent bulb (Sylvania 350BL bulbs, SiemensCorp./Osram Sylvania Inc., Danvers, Conn.) for 30-60 minutes. Thesamples were typically heated to temperatures above their glasstransition temperature during and after light exposure to ensure anacceptable extent of curing. Heating was effected either with an IR heatlamp or in a convection oven.

[0168] Representative homopolymers prepared according to this exampleare shown in Table 1, above, along with observed absorbance/cm⁻¹ for thehomopolymers. Table 2 shows refractive index and optical absorbance datafor selected copolymers of the invention (the structure of whosemonomers has been shown above), prepared as described in this example.TABLE 2 Copolymer Copolymer Monomer 1 Monomer 2 Co- average abs/cm¹abs/cm > 0.01² Compd Compd polymer 1260- 1480- 1260-1360 1480-1580 # Wt% # Wt % n(1.31) 1360 nm 1580 nm nm nm I 44.06 XI 55.74 1.474 .0045 .0181340-1360 1480-1580 VII 83.22 X 16.59 1.447 .002 .005 1345-1360 none Ex.10 45.4 X 54.6 1.459 .004 .005 1355-1360 none Ex. 10 48.46 XI 51.341.458 .0025 .01 1350-1360 1480-1500 VI 31.2 XI 68.8 1.459 .006 .0131345-1360 1480-1580

[0169] The data of Table 2 show that essentially identical refractiveindexes can be obtained for a number of copolymers having distinctlydifferent makeup and low optical absorbances in the desired wavelengthranges can be achieved.

Example 14 Crosslinked Copolymers

[0170] Monomer solutions of pentafluorophenyl acrylate containingvarious weight percentages of three different crosslinkers,trimethylolpropane triacrylate (TMPTA),1,1,5,5-tetrahydrohexafluoropentane-1,5-diol diacrylate (HFPDDA), andtetrafluorohydroquinone diacrylate (TFHQDA), and 0.2 weight percent2,2-diethoxyacetophenone photoinitiator, were prepared. Polymer films,approximately 0.05 mm thick, were prepared from the mixtures by placingthe monomer solutions between polycarbonate release liners that werethen warmed to 80° C. on a hot plate and irradiated for 30 minutes withthe light from two 15 watt fluorescent black lights (F15T8-BLB, GeneralElectric Co., Schenectady, N.Y.) held 7.6 cm above the hot plate.Portions, approximately 25 mm square, were cut from each film sample andweighed. The square portions were then immersed in pentafluorophenylacrylate for 15 minutes, rinsed with isopropanol, blown dry for 10seconds with a stream of nitrogen gas, and weighed. The weight gain uponimmersion in pentafluorophenyl acrylate monomer was taken as a measureof the amount of swelling of the polymer film. The results are shown inTable 3A; each entry represents the average of at least two separatemeasurements. TABLE 3A Crosslinker Crosslinker amount, wt % Average wtgain, % TMPTA  5 55 HFPDDA  5 44 TFHQDA  5 18 TMPTA 10  2 HFPDDA 10 10TFHQDA 10  7

[0171] The data of Table 3 show that fluorinated crosslinkers,especially tetrafluorohydroquinone diacrylate, are useful in reducingthe swelling of polymerized fluorinated acrylate compositions whenplaced in contact with fluorinated acrylate monomers. Reduction inswelling was related to increased dimensional stability of the polymer.

[0172] In a similar fashion, two crosslinkers, TMPTA and FPEGDA, wereevaluated separately using a mixture of pentafluorophenyl acrylate and(perfluorocyclohexyl)acrylate (86/14 wt %). FPEGDA refers toCH₂═CHCOOCH₂(CF₂OCF₂)_(n)CH₂OCOCH═CH₂, n˜6-12 made by acrylation of thediol prepared as in U.S. Pat. No. 5,384,374 by direct fluorination ofdiacetate of poly(ethylene glycol) (av. No. molecular wt of ˜600),methanolysis, and reduction with NaBH4. Because of its high molarvolume, FPEGDA had very low optical loss in the infrared regions ofinterest. Polymer films were tested as above for swelling bypentafluorophenyl acrylate and the data are shown in Table 3B. TABLE 3BCrosslinker Crosslinker amount, wt % Wt % PFPA Absorbed TMPTA 4 45FPEGDA 5 79

Example 15 Preparation of Haloacrylates and Homopolymers Thereof

[0173] Halogenated acrylates of the invention include those based uponthe reaction of acryloyl chloride with: 1) perhalogenated tertiarycarbinols, 2) perhalogenated phenols, and 3) perhalogenated naphthols;and 4) perhalogenated thiophenols.

[0174] Properties of homopolymers of halogenated acrylates havinggeneral formula XXIX based upon the esterification of acrylic acid withperhalogenated tertiary carbinols are shown in Table 4:

CH₂═CHC(O)OCR¹⁰R¹¹R¹²  XXIX

[0175] Haloacrylates described in Table 4 were prepared according tomethods described in Examples 2, 3, 7, 8, 9, and 11. Their structureswere confirmed by spectroscopic analysis. TABLE 4 Homopolymer averageabs/cm¹ average abs/cm > 0.01² 1260-1360 1480-1580 1260-1360 1480-1580Cpd R¹⁰ R¹¹ R¹² n_(1.31) nm nm nm nm 4-1 CF₃ CF₃ C₆F₅ 1.416 .004 .0091350-1360 1575-1580 4-2 CF₃ CFCl₂CFClOCF₂ C₆F₅ 1.441 .003 .003 1355-1360none 4-3 CF₂Cl ClCF₂CF₂OCF₂ C₆F₅ 1.426 — — — — 4-4 CF₂Cl CF₂Cl C₆F₅1.459 — — — — 4-5 C₄F₉OCF₂ C₄F₉OCF₂ C₆F₅ 1.368 — — — — 4-6 CF₃ C₆F₁₃C₆F₅ 1.380 .003 −.006 1357-1360 none 4-7 —CF₂CF₂CF₂CF₂CF₂— C₆F₅ 1.418.004 .002 1340-1360 none 4-8 —CF₂CF₂CF(Cl)CF₂CF₂— C₆F₅ 1.430 — — — — 4-9—CF₂CF₂CF₂CF₂CF₂— C₆F₃Cl₂ 1.446 .003 .003 1345-1360 none 410—CF₂CF₂CF₂CF₂CF₂— C₆F₄Cl 1.423 — — — — 4-11 CF₃ CF₃ C₆Cl₅ 1.530 — — — —4-12 —CF₂CF₂CF₂CF₂CF₂— C₆Cl₅ 1.500 — — — — 4-13 CF₃ CF₃OCF₂ C₆Cl₅ 1.506— — — — 4-14 CF₃ CF₃O-i-C₃F₆OCF₂ C₆Cl₅ 1.450 .002 .004 1355-1360 none4-15 CF₃ CF₃O(C₂F₄O)₂CF₂ C₆Cl₅ 1.444 — — — — 4-16 C₂F₅OCF₂ C₂F₅OCF₂C₆Cl₅ 1.449 — — — — 4-17 C₄F₉OCF₂ C₄F₉OCF₂ C₆Cl₅ 1.420 — — — — 4-18C₄SCl₃ CF₂Cl CF₂Cl 1.525 — — — — 4-19 C₄SCl₃ CF₃ C₆F₁₃ 1.435 — — — —4-20 C₆F₅ C₂F₅ C₆F₅ 1.441 — — — — 4-21 C₆F₅ C₂F₅OC₂F₄OCF₂ C₆F₅ 1.424.006 .06 1350-1360 1480-1580 4-22 C₆F₅ CFCl₂CFClOC₂F₄ C₆F₅ 1.450 — — — —4-23 C₆F₅ C₂F₅OC₂F₄OCF₂ C₆Cl₅ 1.470 — — — — 4-24 C₆F₅ C₂F₅OCF₂ C₆Cl₅1.488 — — — — 4-25 C₂F₅OCF₂ C₂F₅OCF₂ C₆F₅ 1.390 — — — — 4-26—CF₂CF₂CF₂CF₂CF₂— C₆Cl₂F₂— 1.462 — — — — (OC₆F₅)

[0176] The data of Table 4 and Table 5, below, show that the refractiveindex of homopolymers of the invention can be tailored dependent uponchoice of halogenated groups in the structure.

[0177] Properties of halogenated acrylates having general formula XXX,based upon the reaction of acryloyl chloride with perhalogenated phenolsare shown in Table 5:

[0178] Haloacrylates described in Table 5 were prepared according tomethods described in Examples 4, 5, 6, and 10. Their structures wereconfirmed by spectroscopic analysis. TABLE 5 Homopolymer Average Abs/cm¹Average Abs/cm > 0.01² 1480-1580 1480-1580 Cmpd R¹³ R¹⁴ R¹⁵ R¹⁶ R¹⁷n_(1.31) 1260-1360 nm nm 1260-1360 nm nm 5-1 F F F F F 1.465 — — — — 5-2F F Cl F F 1.500 — — — — 5-3 F F CF₃C₆F₄S F F 1.499 — — — — 5-4 F FClC₆F₄O F F 1.503 .006 .007 1348-1360 1480-1500 5-5 F F BrC₆F₄O F F1.512 — — — — 5-6 F F (C₆F₅)CO₂ F F 1.474 — — — — 5-7 CF₃ F F C₆F₅O F1.465 .002 .008 1352-1360 1480-1500 5-8 CF₃ F F ClC₆F₄O F 1.505 — — — —5-9 F F CF₃ F F 1.444 — — — — 5-10 F F C₆F₅ F F 1.477 — — — — 5-11 Cl FCl F Cl 1.547 .003 .005 1350-1360 1480-1485 5-12 Cl Cl Cl Cl Cl 1.550 —— — — 5-13 F F CN F F 1.499 — — — — 5-14 F F C₆F₅S F F 1.508 — — — —5-15 F F I F F 1.548 — — — — 5-16 Br F Br F F 1.558 — — — — 5-17 F F BrF F 1.515 .004 .012 1350-1360 1480-1580 5-18 Br F F Cl F 1.544 — — — —5-19 CF₃ F F Br F 1.487 — — — —

[0179] A perfluorothioacrylate corresponding to formula XXXI wasprepared in a manner essentially as described previously by reaction ofacryloyl chloride with pentafluorothiophenol (c.f., Examples 1, 5, 6,etc.).

[0180] Compound XXXI had a melting point of less than 25° C., and therefractive index (n_(1.31)) of the corresponding homopolymer was 1.516.

Example 16 Preparation of 1,3,5-tribromo-2,4-bisacryloyloxybenzene

[0181] Ten grams of 2,4,6-tribromoresorcinol was dissolved in 150 mL ofacetonitrile and the mixture was cooled to 0° C. Acryloyl chloride (4.7mL) was added and the mixture was magnetically stirred. Triethyl amine(8.0 mL) was then added in a dropwise fashion and the reaction wasmaintained at 0° C. A precipitate formed upon addition of triethylamine. After the triethyl amine addition, the reaction was stirred forone hour at 0° C. and 24 hours at room temperature. The reaction mixturewas filtered and the filtrate was rotary evaporated to a brownish oilysolid. The solid was washed with water and crystallized from hot hexanesto give 12 g (91%) of 1,3,5-tribromo-2,4-bisacryloyloxybenzene ascolorless crystals.

Example 17 Preparation of Tribromopyrogallol Triacrylate (Compound XXV)

[0182] Pyrogallol (10 g) was dissolved in 150 mL of diethyl ether andbromine (12 mL in 50 mL of dichloromethane) was added dropwise over a 2hour period to the stirred solution. The resulting reddish homogeneoussolution was stirred for 16 hours. The reaction mixture was then rotaryevaporated to a light red-brown semicrystalline solid. The solid wasdissolved in 200 mL of diethyl ether and the solution was filtered.Heptane (200 mL) was added to the filtrate and the slightly cloudysolution was allowed to slowly evaporate to form fine, off-white needlesof tribromopyrogallol (27.7 g, 96%).

[0183] Ten grams of tribromopyrogallol was dissolved in 200 mL ofacetonitrile and the mixture was cooled to 0° C. Acryloyl chloride (8mL) was added and the mixture was magnetically stirred. Triethyl amine(13 mL) was then added in a dropwise fashion and the reaction wasmaintained at 0° C. A precipitate formed upon addition of triethylamine. After the triethyl amine addition, the reaction was stirred forone hour at 0° C. and 16 hours at room temperature. The reaction mixturewas filtered and the filtrate was rotary evaporated to a yellowish oil.The oil was washed with water and crystallized from hot hexanes to give6.2 g (43%) of tribromopyrogallol triacrylate as colorless needles.

Example 18 Preparation of Tribromophloroglucinol Triacrylate (CompoundXXIV)

[0184] Phloroglucinol dihydrate (10 g) was suspended in 150 mL ofdichloromethane and bromine (12 mL in 50 mL of dichloromethane) wasadded dropwise over 2.5 hour period to the stirred suspension. Thesuspended phloroglucinol dissolved during the course of the bromineaddition. After stirring for an additional 2 hours a two-phase solutionwas obtained. The pale orange dichloromethane supernatant solution wasdecanted from a small amount of a denser, dark red aqueous solution. Thedichloromethane solution was rotary evaporated to a pinkish coloredsemicrystalline solid. The solid was dissolved in a 50 mL of acetone and500 mL of heptane was slowly added with stirring to give beige crystalsof tribromophloroglucinol (18.8 g, 84%).

[0185] Ten grams of tribromophloroglucinol was dissolved in 150 mL ofacetonitrile and the mixture was cooled to 0° C. Acryloyl chloride (8mL) was added and the mixture was magnetically stirred. Triethyl amine(13 mL) was then added in a dropwise fashion and the reaction wasmaintained at 0° C. A precipitate formed upon addition of triethylamine. After the triethyl amine addition, the reaction was stirred forone hour at 0° C. and 2 hours at room temperature. The reaction mixturewas poured into ice water and a cream colored semicrystallineprecipitate formed. The precipitate was collected by filtration, washedwith water, and air dried. The solid was crystallized from hot heptanesto give 6.1 g (42%) of tribromophloroglucinol triacrylate as off-whiteneedles.

Example 19 Use of Brominated Crosslinkers to Modify the Refractive Indexof Hydrocarbon Acrylates

[0186] Tetrabromocatechol diacrylate (Example 12) (1.0019 g) wasdissolved in 3.9905 g phenoxyethyl acrylate (PEA) (CPS Chemical Co., OldBridge, N.J.) to give a solution containing approximately 20% by weightof the diacrylate crosslinker. Tribromophloroglucinol triacrylate(Example 18) (0.4995 g) was dissolved in 2.0120 g PEA to give a solutioncontaining approximately 20% by weight of the triacrylate crosslinker.DEAP photoinitiator (0.2% by weight) was added to the solutions and to asample of pure PEA. Portions of these three samples were polymerized andthe refractive indices of the polymers were measured as described above.The polymerized PEA gave a refractive index at 1.31 nm of 1.545. Thepolymerized PEA/20 wt % tetrabromocatechol diacrylate gave a refractiveindex at 1.31 nm of 1.561. The polymerized PEA/20 wt %tribromophloroglucinol triacrylate gave a refractive index at 1.31 nm of1.555. Using the measured refractive index of PEA and calculateddensities for the brominated crosslinkers (by methods known in the art),refractive indices were calculated for the homopolymers derived from thebrominated crosslinkers. By this method a refractive index at 1.31 nm of1.693 was calculated for polymerized tetrabromocatechol diacrylate and arefractive index at 1.31 nm of 1.628 was calculated for polymerizedtribromophloroglucinol triacrylate. This example shows that thebrominated crosslinkers can be used to crosslink acrylate monomers andthat they are effective in increasing the refractive index of theresulting polymer.

Example 20 Use of Brominated Crosslinkers to Modify the Glass TransitionTemperatures (Tg) of Hydrocarbon Acrylates

[0187] Tetrabromocatechol diacrylate (Example 12) (0.5084 g) wasdissolved in 4.5006 g isobornyl acrylate (IBA) (San Esters Corp., NY) togive a solution containing approximately 10% by weight of the diacrylatecrosslinker. Tribromophloroglucinol triacrylate (Example 18) (0.5051 g)was dissolved in 4.4952 g IBA to give a solution containingapproximately 10% by weight of the triacrylate crosslinker. DEAPphotoinitiator (0.2% by weight) was added to the solutions and to asample of pure IBA. Portions of these three samples were polymerized andthe Tgs of the polymers were measured as described above. The Tg ofpolymerized IBA was found to be 62.5° C. The Tg of IBA copolymerizedwith 10 wt % tetrabromocatechol diacrylate was found to be 98.5° C. TheTg of IBA copolymerized with 10 wt % tribromophloroglucinol triacrylatewas found to be 96° C. This example shows that the brominatedcrosslinkers can be used to crosslink acrylate monomers and that theyare effective in increasing the glass transition temperature of theresulting polymer.

Example 21 1-(1,2,2-trichloro-1,2-difluoroethoxy)perfluoroacetone

[0188] A mixture of 339 g trichloroethanol, 291 g propylene oxide and17.7 g dry triethylamine was stirred in a 1-liter round bottom flask at23° C. for four days, then washed with 2×400 mL 10% aq. HCl and 1×400 mLsat. aq. NaCl solution. The remaining organic solution was diluted with200 mL methylene chloride and dried over MgSO₄. The filtered solutionwas treated with a slight excess of trifluoroacetic anhydride, afterwhich the solvent was removed and the residue distilled at 66° C. and 20Pa to yield the corresponding trifluoromethyl acetate. The acetate wastaken up in perfluoro N-methyl morpholine (PNMM, 3M Company, St. Paul,Minn.) and subjected to direct fluorination, as described in thepreviously-incorporated Example 1 of U.S. Pat. No. 5,236,919. Thefluorinated ester was converted to the corresponding methyl hemi-ketalby addition of BF₃/MeOH, and the hemi-ketal was converted to the desiredketone by distillation from conc. H₂SO₄. The structure of the ketone wasverified by IR and ¹⁹F NMR spectra.

Example 22 2-Acryloyloxy-2-pentafluorophenylperfluorooctane (CompoundVIII)

[0189] An ethereal solution of pentafluorophenyl magnesium chloride wasprepared from 20.2 g C₆F₅Cl, 4.8 g Mg and 100 mL diethyl ether(exothermic after initiation with BrC₂H₄Br). A dry-ice condenser wasattached and 41.6 g perfluorooctanone (prepared according to the methoddescribed in U.S. Pat. No. 5,236,919, Example 1, incorporated herein byreference) was introduced directly into the solution. The reactionmixture was stirred overnight, then treated with dilute aq. HCl anddistilled to give 45 g of the desired2-pentafluorophenylperfluorooctan-2-ol at 78° C./67 Pa. A mixture of 29g of the alcohol and 4.5 mL acryloyl chloride in 300 mL diethyl etherwas treated with 5.05 g triethylamine at 0° C. and allowed to warm to23° C. overnight with stirring. The reaction mixture was washed withwater, dried over MgSO₄, and stripped of solvent. Purification on asilica gel column (CH₂Cl₂/C₆H₁₄; 1/3) and distillation at 85° C./1.0 Pagave 21 g colorless liquid acrylate, confirmed by spectroscopicanalysis.

Example 231-{(2-trifluoromethoxytetrafluoroethoxy)tetrafluoroethoxy}pentafluoroacetoneCF₃OCF₂CF₂OCF₂CF₂OCF₂—CO—CF₃

[0190] A mixture of 300 g 2-(2-methoxyethoxy)ethanol (Methyl Carbitol™),174 g of propylene oxide, 17 ml of freshly distilled triethylamine, and1 g of Adogen™ 464 phase transfer catalyst was sealed in a glass reactorand the mixture was left to stir for 4 days, then heated to 55° C. for10 hours. Gas chromatography (GC) showed 77% conversion to the desiredproduct with 7.5% starting alcohol and 15% higher homolog. The reactionmixture was diluted with 500 mL of CH₂Cl₂ after which 250 mL of acetylchloride was added dropwise to the stirred mixture with icebath cooling.The organic phase was washed with 700 mL of H₂O and 750 mL saturatedNaCl solution. After rotary evaporation, the residue was distilled undervacuum (115 to 135° C./120 Pa) to yield a 247 g of distillate that was85% pure desired polyether acetate. Direct fluorination of the acetategave a crude product that was treated with an excess of methanol to formthe methyl hemi-ketal (CF₃OCF₂CF₂OCF₂CF₂OCF₂—C(OH)(OCH₃)CF₃). Thehemi-ketal was isolated by distillation (245.1 g), then distilled from250 ml of concentrated H₂SO₄. The fraction from 99 to 106° C. (129.1 g)contained 91.6% desired ketone by GC. The material was characterized byIR and fluorine NMR.

Example 24 2,2,2-trichloro-1-(chloro(difluoro)methyl)-1-((2-chloro-1,1,2,2-tetrafluoroethoxy)(difluoro)methyl acrylate (Compound XVII)

[0191] In a manner similar to that described as method B by Zeifman et.al., Izv. Akad. Nauk, Ser. Khim, 2, 464-468 (1992), 31.5 g of thefluorochloroketone ClCF₂CF₂OCF₂—CO—CF₂Cl, synthesized from chloroethanoland epichlorohydrin in the manner described in Example 23, was added toa pre-dried reaction vessel containing 32.7 g of trichloroacetic acid in100 mL hexamethylphosphoramide at 23° C. The solution was warmed to 60°C. until no additional CO₂ evolution was observed, then stirred 14 hoursat 23° C. The mixture was quenched with 200 mL of 10% HCl solution andthe organic layer was extracted into 100 mL of ethyl ether. The etherfraction was washed with 3×100 mL of dilute HCl solution, dried overMgSO4 and evaporated with rotary evaporation. The residue (42.6 g) wasdistilled (58-62° C. /173 Pa) to yield 7.7 g of carbinol (18%). Thismaterial was combined with that from a second run (6.3 g) and thecombined carbinol (13.1 g) was dissolved into 50 mL of CH₂Cl₂ to whichwas added 3.8 mL of acryloyl chloride with icebath cooling. 4.8 g ofdried triethylamine was added dropwise with stirring and the entiremixture was allowed to warm to 23° C. The mixture was washed withsaturated NaCl solution, dried over MgSO₄, filtered, solvent strippedand then purified by column chromatography (silica gel, 230-400 mesh, 60Å) using hexanes:ethyl acetate (8:1 by volume). 13 g of clear colorlessacrylate was isolated. The structure was confirmed by proton andfluorine NMR and GC/MS. The clear colorless liquid was polymerized togive a clear solid homopolymer having n_(1.31)=1.443.

Example 252,2,3,3,4,4,5,5,6,6-decafluoro-1-(trichloromethyl)-1-cyclohexanol(Compound XVIII)

[0192] A solution of 30 g of perfluorocyclohexanone and 31.7 g oftrichloroacetic acid was stirred in a pre-dried reaction vesselcontaining 113 mL of hexamethylphosphoramide. This mixture was cooled to−10° C. in a dry ice/acetone bath. Slight gas evolution was noted beforeand during the ketone addition. The stirred milky white reaction mixturewas maintained at about 0° C. for an hour and then allowed to warm to23° C. and stirring was continued 17 hours. The clear yellow solutionwas quenched with 150 mL of 10% HCl and then transferred to a separatoryfunnel with 400 mL of ethyl ether. This organic phase was washed with4×500 mL of dilute HCl and then 300 mL of saturated NaCl solution. Thesolvent was removed by evaporation. The residue (33.7 g) contained 40.8%product by GC, confirmed by fluorine NMR. This carbinol can be convertedto the corresponding acrylate by methods previously described (cf.Example 24).

Example 26 2,2,2-trichloro-1,1-di(2,3,4,5,6-pentafluorophenyl)-1-ethanoland (Compound XIX)

[0193] A mixture of 4.9 g of decafluorobenzophenone and 2.7 g oftrichloroacetic acid was added to 15 mL of hexamethylphosphoramide. Thestirred reaction mixture was maintained at about 0° C. for about 2 hoursand then allowed to warm to room temperature and continue stirring atambient temperature for the next 15 hours. The reaction mixture wascharacterized by GC and fluorine NMR to show a conversion ofapproximately 20% to the desired carbinol. This carbinol can beconverted to the corresponding acrylate by methods previously described(cf. Example 24).

Example 27 CF₃CH(OC(O)CH═CH₂)CF₂O(CF₂)₄OCF₂CH(OC(O)CH═CH₂)CF₃ (CompoundXXVII)

[0194] A solution of 100 g of butane diol and 18 g of freshly distilledtriethylamine was transferred into a 600 mL Parr reactor, followed by135.3 g of propylene oxide. The reaction vessel was sealed and thesolution was stirred and heated to 50° C. Within the first 35 minutes anexotherm began and the reaction mixture self heated to 140° C. Thereaction slowly cooled to 50° C. and was maintained at this temperaturefor a total of 36 hours. An additional 40 mL of propylene oxide wasadded and the reaction was re-heated to 50° C. and left with stirringand heating for 24 hours. The contents of the reaction vessel weretransferred into a 1000 mL 3-neck round-bottom flask with 150 mL ofCH₂Cl₂. 200 mL of acetyl chloride was added to the stirred mixture withicebath cooling. After the addition, the icebath was removed and themixture allowed to stir for 1 hour at 23° C. The mixture was washed with400 mL of H₂O, 400 mL of saturated NaCl solution, then dried over MgSO₄.147.7 g of the desired acetate was isolated by distillation (Bp=124 to145° C./160 Pa). The structure was verified by proton NMR. Thehydrocarbon acetate was fluorinated, isolated, and converted to thediketone as previously described in Example 23. The diketone can beconverted to a diacrylate as described in U.S. Pat. No. 3,520,863,Example 15, incorporated herein by reference.

[0195] 150 g of glycerol was weighed into a 600 mL Parr reactor. 250 mL(208 g) of propylene oxide was charged into the glycerol followed by22.7 mL (16.5 g ) of freshly distilled triethylamine. The solution wasstirred and heated to 50° C. for one hour, after which the temperaturewas raised to 70° C. An exotherm followed with a maximum temperature of135° C. The mixture was stirred at of 70° C. for the next 18 hours. Thereactor was cooled to 23° C. and the excess pressure vented into a hood.No glycerol triacetate was observed by GC, so the contents of thereaction vessel were transferred into a 1000 mL 3-neck round-bottomflask with 350 mL of CH₂Cl₂, and 360 mL of acetyl chloride were added tothe stirred mixture with icebath cooling. After the addition, theicebath was removed and the mixture allowed to stir for 1 hour at roomtemperature. The mixture was washed with 800 mL of H₂O, 500 mL ofsaturated NaCl solution, and dried over MgSO₄. rotary evaporation ofsolvent gave a yellow residue (561.5 g). Distillation (166 to 188° C./160 Pa) gave 234 g of product that was found to comprise a mixture of7% trifunctional with 1 propylene oxide group to 1 glycerol group (1:1,PO:Gly), 57% desired tri-functional (2:1, PO:Gly.), 29% trifunctional(3:1, PO:Gly.), and the balance of higher oligomers. The structures wereverified by proton NMR. The hydrocarbon acetate was fluorinated,isolated, converted to the corresponding polyketone as previouslydescribed in Example 23. The polyketone can be converted to apolyacrylate as described in U.S. Pat. No. 3,520,863, Example 15,incorporated herein by reference.

Example 29 4-Pentafluorobenzoyloxy-2,3,5,6-tetrafluorophenyl Acrylate

[0196] A mixture of 56.0 g C₆F₆ in 300 mL 1M KOtBu/tBuOH heated atreflux 1 hr, and the organic product was recovered by washing with waterand extraction with methylene chloride. The MgSO₄-dried extract wasstripped on a rotary evaporator to give 48.6 g of tan liquid, 92%C₆F₅OtBu and 4% di-t-butoxytetrafluorobenzene isomers by GC. Of this,42.4 g was stirred at 60° for 22 hr with 25.0 g powdered KOH in 65 mLt-BuOH. Acidification of an aliquot of the cooled product showed 40%recovery, 20% desired phenol, and 40% byproductdi-t-butoxytetrafluorobenzene isomers. The phenol was separated bywashing the reaction product with water and subsequently acidifying thecollected water wash to yield 13.0 g of hydroxy-tetrafluorophenylt-butyl ethers. A prior sample was analyzed by gc/ms and ¹⁹F NMR andassigned as the para isomer (77%) and meta isomer (23%). 11.6 g wasdissolved in 150 mL CH₂Cl₂, chilled in ice, treated with 8.0 mLtriethylamine, and then treated dropwise with 12.0 g C₆F₅COCl. This wasleft standing for 3 days. Water washing, drying, and stripping gave 21.3g low-melting solid, pentafluorobenzoyloxytetrafluorophenyl t-butylether. This was mixed with 23 mL trifluoroacetic acid and 2 mL water,warmed on a steam bath for 1.5 hr, and quenched in water and extractedwith CH₂Cl₂, dried, and stripped to 18.6 g tan oil,pentafluorobenzoyloxytetrafluorophenol, confirmed by ¹⁹F NMR. This wasdissolved in 150 mL CH₂Cl₂, 5.0 mL acryloyl chloride was added, and theice-cooled mixture was treated with 10.0 mL triethylamine over about 1min. Chromatography on 400 mL silica gel with hexane yielded the acylateas a slightly yellow liquid, 11.3 g. The structure of the desiredacrylate was confirmed by spectroscopy.

Example 303,12-Diacryloxy-3,12-Dihydrido-perfluoro-2,13-Dimethyltetradecane(CF₃)₂CFCH(OCOCH═CH₂)(CF₂)₈CH(OCOCH═CH₂)CF(CF₃)₂ (Compound XXXII)

[0197] Based on the chemistry reported by Smith, Fawcett, & Coffman,JACS, 84, p4285 (1962); the ketone, (CF₃)₂CF—CO—(CF₂)₈—CO—CF(CF₃)₂, wassynthesized as follows. 50 g of the di-acid fluoride (F—CO—(CF₂)₈—CO—F)was charged into a 600 ml Parr reactor with 0.6 g of anhydrous KF and 54g of anhydrous diglyme. The reactor was sealed and cooled in dry ice. 33g of hexafluoropropene was charged into the reactor. The reactor washeated to 100 degrees C. over a period of 28 hours. The reactor wascooled and vented and the lower fluorochemical phase isolated (75.6 g,94% yield) and washed with saturated NaCl solution. The organic wasdried over MgSO₄, filtered and distilled. A sample of the main cut(colorless clear low melting crystals) was characterized by 19F-NMR andIR. 32 g of this ketone was dissolved in 150 mL of anhydrous diglyme.3.1 g of NaBH₄, suspended in 20 mL of diglyme was added in 1 mLaliquots. The mixture was left to stir for 4 hours with water bathcooling to control the exotherm. The resulting heterogeneous mixture wasdecomposed with 5% HCl. The lower phase was isolated and the residualdiglyme distilled to leave 28.8 g (89% yield) of a yellow solid. Thissolid was characterized by proton and fluorine NMR and IR to confirm thestructure. 24 g of the solid was dissolved in 50 mL anhydrous CH₃CNunder a nitrogen atmosphere and charged with 6 g of acryloyl chloride at5 degrees C. 6.7 g of triethyl amine was added dropwise to the stirredsolution. The solid amine hydrochloride by-product was removed byfiltration and 100 ml of CH₂Cl₂ was added and the organic layer washedwith saturated NaCl solution. The organic was then solvent stripped byrotary evaporation to leave the crude diacrylate. The structure wasverified by proton and fluorine NMR.

[0198] Various modifications and alterations that do not depart from thescope and spirit of this invention will become apparent to those skilledin the art. This invention is not to be unduly limited to theillustrative embodiments set forth herein.

We claim:
 1. A halogenated acrylate having the general formula

wherein M is H, CH₃, F, Cl, Br, I, or CF₃, A is oxygen or sulfur, and Zis a group having at most 150 carbon atoms selected from the groupconsisting of

in which each R¹ independently is F, Cl, or Br;

in which each R² independently is (a) a perfluorinated, perchlorinated,or per(chlorofluoro) group (i), (ii), (iii), (iv), or (v) wherein (i) isa C₁-C₂₀ aliphatic group, (ii) is a C₃ to C₂₀ cycloaliphatic alkylgroup, (iii) is a C₆-C₂₀ aryl group, (iv) is a C₇-C₂₀ aralkyl group, and(v) is a C₇-C₂₀ alkaryl group, (b) F, Cl, Br, I, Q (defined below),R⁴COO—, R⁴O—, —COOR⁴, —OSO₂R⁴, or —SO₂OR⁴, wherein R⁴ is any group from(a)(i), (a)(ii), (a)(iii), (a)(iv), and (a)(v), or any two adjacent R²groups together can form a perfluorinated, perchlorinated, orper(chlorofluoro) cycloaliphatic or aromatic ring moiety whichoptionally can further include n R² groups where n is a whole number inthe range of 0 to 25 that describes the number of free sites on the ringmoiety, wherein Q is

in which A is as defined as above, with the proviso that all R² groupsin the molecule can be the same only when R² is not Cl, F, Br or I; andeach R³ independently can be (a) a perfluorinated, perchlorinated, orper(chlorofluoro) (i) C₁-C₂₀ aliphatic group, (ii) C₃-C₂₀ cycloaliphaticgroup, (iii) C₆-C₂₀ aryl group, (iv) C₇-C₂₀ aralkyl group, and (v)C₇-C₂₀ alkaryl group, (b) F, Cl, Br, I, Q (defined above), R⁴COO—, R⁴O—,—COOR⁴, —OSO₂R⁴, or —SO₂OR⁴, wherein R⁴ is any group from (a)(i),(a)(ii), (a)(iii), (a)(iv), and (a)(v), or any two adjacent R³ groupstogether can form a perfluorinated, perchlorinated, or per(chlorofluoro)cycloaliphatic or aromatic ring moiety which optionally can furtherinclude n R³ groups where n is a whole number in the range of 0 to 25that describes the number of free sites on the ring moiety; (3)—C(R_(f))₂E in which both R_(f) groups together are part of aperfluorinated, perchlorinated, or per(chlorofluoro) cycloaliphatic ringgroup or independently are perfluorinated, perchlorinated, orper(chlorofluoro) (a) C₁-C₂₀ aliphatic groups, (b) C₃-C₂₀ cycloaliphaticgroups, (c) C₆-C₂₀ aryl groups, (d) C₇-C₂₀ aralkyl groups, or (e) C₇-C₂₀alkaryl groups, (f) C₄-C₂₀ heteroaryl groups, (g) C₄-C₂₀ heteroaralkylgroups, (h) C₄-C₂₀ heteroalkaryl groups, wherein heteroatoms can be oneor more of O, N, and S atoms, with the proviso that at least one R_(f)group includes one or more of (i) at least one straight-chain C₄-C₂₀aliphatic or C₄-C₂₀ cycloaliphatic group, (ii) at least one ether oxygenatom, and (iii) at least one branched C₃-C₂₀ aliphatic group, and E isR_(f),

wherein R¹, R², and R_(f), and Q are defined as above, and (4)—CR_(f)(E)₂, wherein each E independently is as defined above, and R_(f)is as defined above.
 2. The halogenated acrylate according to claim 1wherein A is oxygen.
 3. The halogenated acrylate according to claim 1wherein M is hydrogen.
 4. The halogenated acrylate according to claim 1wherein Z is —C(R_(f))₂E, wherein each R_(f) group independently and Eare as defined above.
 5. The halogenated acrylate according to claim 1wherein A is O (oxygen) and Z is

and each R² and R³ is independently one of F, Cl, and CF₃.
 6. Thehalogenated acrylate according to claim 1 wherein Z is

wherein each R² is as previously defined.
 7. The halogenated acrylateaccording to claim 2 wherein Z is —C(R_(f))₂E and wherein each R_(f)independently and E are as previously defined.
 8. The halogenatedacrylate according to claim 2 wherein Z is

wherein each R² is as previously defined.
 9. The halogenated acrylateaccording to claim 7 having the formula

wherein one R_(f) group comprises a C₄-C₂₀ aliphatic or C₄-C₂₀cycloaliphatic group and the second R_(f) group comprises at least oneether oxygen atom or a C₃-C₂₀ branched aliphatic group, and E is aspreviously defined.
 10. The halogenated acrylate according to claim 7wherein E is

and R² is previously defined.
 11. The halogenated acrylate according toclaim 9 wherein each R_(f) group independently is a perhalogenatedphenyl group and E is a C₁-C₂₀ perhalogenated aliphatic group comprisingat least one ether oxygen atom.
 12. The halogenated acylate of claim 9wherein both R_(f) groups together form a perhalogenated cyclohexylgroup and E is a perhalogenated phenyl group.
 13. The halogenatedacrylate according to claim 10 wherein each R² is F.
 14. The halogenatedacrylate according to claim 6 wherein at least one R² is selected fromthe group consisting of F, OC₆F₅, SC₆F₄CF₃, OC(O)C₆F₅, and OSO₂C₄F₉. 15.The halogenated acrylate according to claim 8 wherein at least one R² isselected from the group consisting of F, OC₆F₅, SC₆F₄CF₃, OC(O)CF₃, andOSO₂CF₃.
 16. A halogenated acrylate having structure selected from thegroup consisting of


17. A halogenated acrylate having a structure selected from the groupconsisting of


18. The halogenated acrylate according to claim 1 wherein M is H, F, orCl.
 19. A polymer comprising at least one mer unit derived bypolymerization of the olefinic bond from a halogenated acrylate havingthe general formula

wherein A is oxygen or sulfur, and Z is a group having at most 150carbon atoms selected from the group consisting of (1)

in which each R¹ independently is F, Cl, or Br; (2)

in which each R² independently is (a) a perfluorinated, perchlorinated,or per(chlorofluoro) group (i), (ii), (iii), (iv), or (v) wherein (i) isa C₁-C₂₀ aliphatic group, (ii) is a C₃ to C₂₀ cycloaliphatic alkylgroup, (iii) is a C₆-C₂₀ aryl group, (iv) is a C₇-C₂₀ aralkyl group, and(v) is a C₇-C₂₀ alkaryl group, (b) F, Cl, Br, I, Q (defined below),R⁴COO—, R⁴O—, —COOR⁴, —OSO₂R⁴, or —SO₂OR⁴, wherein R⁴ is any group from(a)(i), (a)(ii), (a)(iii), (a)(iv), and (a)(v), or any two adjacent R²groups together can form a perfluorinated, perchlorinated, orper(chlorofluoro) cycloaliphatic or aromatic ring moiety in which nfluoro or chloro groups optionally can be replaced by n R² groups wheren is a whole number in the range of 0 to 25, wherein Q is

in which A is as defined as above, with the proviso that all R² groupsin the molecule can be the same only when R² is not Cl, F, Br or I; andeach R³ independently can be (a) a perfluorinated, perchlorinated, orper(chlorofluoro) (i) C₁-C₂₀ aliphatic group, (ii) C₃-C₂₀ cycloaliphaticgroup, (iii) C₆-C₂₀ aryl group, (iv) C₇-C₂₀ aralkyl group, and (v)C₇-C₂₀ alkaryl group, (b) F, Cl, Br, I, Q (defined above), R⁴COO—, R⁴O—,—COOR⁴, —OSO₂R⁴, or —SO₂OR⁴, wherein R⁴ is any group from (a)(i),(a)(ii), (a)(iii), (a)(iv), and (a)(v), or any two adjacent R³ groupstogether can form a perfluorinated, perchlorinated, or per(chlorofluoro)cycloaliphatic or aromatic ring moiety in which n fluoro or chlorogroups which can be replaced by n R³ groups wherein n is a whole numberin the range of 0 to 25, and R³ is as defined above; (3) —C(R_(f))₂Ewherein both R_(f) groups together comprise a perfluorinated,perchlorinated, or per(chlorofluoro) cycloaliphatic ring group orindependently comprise perfluorinated, perchlorinated, orper(chlorofluoro) (a) C₁-C₂₀ aliphatic groups, (b) C₃-C₂₀ cycloaliphaticgroups, (c) C₆-C₂₀ aryl groups, (d) C₇-C₂₀ aralkyl groups, or (e) C₇-C₂₀alkaryl groups, (f) C₄-C₂₀ heteroaryl groups, (g) C₄-C₂₀ heteroaralkylgroups, (h) C₄-C₂₀ heteroalkaryl groups, wherein heteroatoms can be oneor more of O, N, and S atoms, with the proviso that at least one R_(f)group includes one or more of (i) at least one straight-chain C₄-C₂₀aliphatic or C₄-C₂₀ cycloaliphatic group, (ii) at least one ether oxygenatom, and (iii) at least one branched C₃-C₂₀ aliphatic group, and E isR_(f),

wherein R¹, R², and R_(f), and Q are defined as above, and (4)—CR_(f)(E)₂, wherein each E independently is as defined above, and R_(f)is as defined above.
 20. The polymer according to claim 19 which hasbeen crosslinked by polyfunctional halogenated acrylates.
 21. Thepolymer according to claim 20 wherein said polyfunctional halogenatedacrylates have the formula R⁹ _(f)CR¹⁸R_(f)(OC(O)CH═CH₂)_(q) wherein R⁹_(f) is an acyclic aliphatic halogenated group, free of unsaturation,having at least 1 carbon atom and optionally O, N, or S atoms in thealiphatic group.
 22. The polymer according to claim 20 wherein saidpolyfunctional halogenated acrylates are selected from the groupconsisting of brominated aromatic polyacrylates and acyclic aliphatichalogenated polyol polyacrylates.
 23. The polymer according to claim 20wherein said polyfunctional halogenated acrylates are selected from thegroup consisting of

CF₃CH(OC(O)CH═CH₂)CF₂O(CF₂)₄OCF₂CH(OC(O)CH═CH₂)CF₃,and  XXVIICF₃CF(OC(O)CH═CH₂)CF₂OCF₂CF(OC(O)CH═CH₂)CF₂OCF₂CF(OC(O)CH═CH₂)CF₃,and  XXVIII corresponding methacrylates of these structures. 24.Polyfunctional halogenated acrylates having structures selected from thegroup consisting of

CF₃CF(OC(O)CH═CH₂)CF₂O(CF₂)₄OCF₂CF(OC(O)CH═CH₂)CF₃,and  XXVIICF₃CF(OC(O)CH═CH₂)CF₂OCF₂CF(OC(O)CH═CH₂)CF₂OCF₂CF(OC(O)CH═CH₂)CF₃,  XXVIIIand corresponding methacrylates of these structures.
 25. A method ofpreparing ClCF₂CFClOR⁸ _(f) and Cl₂CFCFClOR⁸ _(f) comprising the step ofdirect fluorination of Cl₂CHCH₂OR⁸ and Cl₃CCH₂OR⁸, respectively, whereinR⁸ is a C₁-C₂₀ alkyl- or acyl-containing group optionally containing upto 5 ether oxygen atoms and R⁸ _(f) is the corresponding perfluoroalkylor perfluoracyl-containing group, optionally containing up to 5 etheroxygen atoms.
 26. The method according to claim 25 wherein R⁸ _(f)comprises in the range 1 to 12 carbon atoms and optionally issubstituted by at least one SO₂F and COF group.
 27. A perfluorinatedketone having the structure R⁵ _(f)CF₂COCF₃, R⁵ _(f)OCF₂COCF₂Cl, or R⁵_(f)OCF₂COCF₂OR⁵ _(f), wherein R⁵ _(f) is a linear perfluoroalkyl orperfluorooxyalkyl group having in the range of 2 to 20 carbon atoms. 28.An optical device comprising a polymer according to claim 19 .
 29. Anoptical device comprising a polymer according to claim 20 .